Some concepts for new kinds of military systems:
* Supersonic transports that are military versions of the soon to be introduced Boom company supersonic long range commercial airliners for trans-Pacific and trans-Atlantic flights. Smaller, somewhat faster, versions of these could be developed to use for med-evac, especially in the Pacific theater where there are vast distances between trauma center class hospitals.
* Very small missile boats that are fast, don't have naval guns or torpedos, and house crews who are not on shift, provisions, and fuel on "mother ships" (either submarines or surface ships) further from the immediate theater of expected conflict. They would each have just one battery of anti-ship/anti-surface missiles each, plus air defense/anti-missile resources. Numerous missile boats would be procured, but they would be under 800 tons each, similar to China's 220 ton, 43 meter, Type 22 missile boats or Finland's 250 ton, 51 meter, Hamina class missile boats. When defending the littorals of allies, the "mother ship" wouldn't be needed. By comparison, the smallest surface combatants in the U.S. Navy are the littoral combat ships (LCS) at about 3000 tons each, which often don't have anti-ship missiles sufficient to take down opposing surface combatants at all. In some ways, the concept would be similar to an "arsenal ship" but without putting all of the Navy's eggs in one basket, thus requiring more anti-ship resources to wipe out.
The dominant cargo carried by freight rail in the United States is coal delivered to electric utilities, a dramatically contracting market. This uses rail because it is the cheapest option, because last-mile delivery isn't much of a concern, and because the demand isn't very time dependent since utility power plants can stockpile coal.
But this means that there is little incentive to improve the very slow speed of freight rail which is slower than it was in the 1950s and maybe averages 45 miles per hour.
A very large share of all other freight goes by long haul trucking instead, even though it is more expensive, because it is faster and provides point to point delivery.
Amtrak, outside the Northeast Corridor, shares tracks with freight rail to reduce infrastructure costs, but this makes Amtrak passenger rail slower than passenger rail was in the 1950s and unreliable. As a result, even with heavy subsidies, non-NE corridor Amtrak service has a tiny market share, because it isn't speed and reliability competitive with cars, buses and trains, even though it pays basically nothing for the freight rail tracks it uses.
This is a shame, because rail of all kinds has high fixed costs and low variable costs per trip, so the higher the volume of traffic it gets, the less expensive it is per passenger mile. Even as it is, if Amtrak trains outside the NE-corridor ran full, the cost per passenger mile would be much lower and the immense subsidies per passenger mile on many routes could be greatly reduced.
All other things being equal, however, having freight and passenger rail share rails is efficient, and unless your passenger rail volume is very high, if the two kinds of trains are traveling at similar speed, it isn't a problem. It is a problem for freight and passenger rail lines to share tracks now primarily because the speed and reliability standards for freight lines delivering mostly bulk products like coal are low in the interests of keeping costs as low as possible for low value cargo.
But imagine a post-coal world.
What if we basically started over from scratch rebuilding a combined passenger-freight rail system with far fewer rail crossings over busy roads, that was designed for highly reliable 125 mile per hour to 150 mile per hour speeds for both freight and passenger trains, pulled by electric powered locomotives (whose electricity was generated with greener power grids)?
This could capture a large share of traffic that currently travels via interstate highways, and a large share of short to medium distance air travel, by offering greater speeds for freight and faster trips for passengers (who would also escape the long security lines and boarding process of airplanes).
This would have to be combined with a system of last-mile regional/metro-area scale transportation that would take shipping contain sized rail cars and passengers from train stations to their final destinations. But for passengers, services like Uber and Lyft, as well as on demand car share systems, in addition to traditional car rentals and existing intracity transit options, could meet this need and could grow to meet demand. And, containerized shipping by a mix of rail and trucks is not exactly a radical new technological innovation. Reducing the amount of long haul trucking needed would also favor a conversion of more of the trucking industry to electric vehicles.
Passenger trains, run full, are faster than cars, are vastly more environmentally friendly, and result in far fewer transportation related deaths. If the trains ran full, they could be cheaper per passenger mile than driving too.
The cost of maintaining a mixed passenger rail-freight rail system for 125-150 mile per hour rail service in good condition would be cheaper than the cost of maintaining an interstate highway and major state highway system designed to serve that much traffic, although the major upgrade of the rail system would have to be compete with the sunk costs of the initial build out of the interstate highway system. It would also remove the pressure to build more and bigger intercity highways in the status quo as traffic was diverted to rail.
But if the interstate passenger-freight rail system were upgraded in this way, the scope and scale of and use of the interstate highway and major state highway system could be greatly reduced, which would ultimately reduce the maintenance costs for those major intercity road networks. The trucking jobs that remained would place far less of a strain the truckers and their families, as short-haul truckers, who would become a much larger share of the overall trucking industry, wouldn't have to spend lots of nights on the road, far from home.
The federal government will provide $500,000 in seed money to help kick-start construction of Colorado’s Front Range Passenger Rail project between Fort Collins and Pueblo — a decision that brings the prospect of millions more in future funding.
The U.S. Department of Transportation and the Federal Railroad Administration are set to announce that the rail project will be included in the Corridor Identification and Development Program, according to a news release issued Wednesday by U.S. Rep. Joe Neguse, a Democrat from Lafayette. The program is a major component of the 2021 Bipartisan Infrastructure Law that aims to facilitate the development of intercity passenger rail corridors across the nation. Front Range rail’s inclusion could mean significant money from the federal government over the coming years as the project moves closer to reality.
Among its chief boosters is Gov. Jared Polis. “This corridor stretches across more than 160 miles, connecting 13 of the most populous counties across the state and acting as a transportation ‘spine’ for the Front Range,” Neguse said in a statement. “I am excited to see this project become a reality for our growing communities.” . . .
Early estimates have put the cost for a starter system — likely to be operated by Amtrak in a partnership — at $1.7 billion to $2.8 billion, with as many as six trains a day running mostly on shared freight tracks connecting cities including Pueblo, Colorado Springs, Denver and Fort Collins.The first passenger trains between Fort Collins and Pueblo could be rolling within the next decade, Karsian said. Later upgrades to speed up service and add more frequent trains would add billions of dollars to the cost.
From the Denver Post.
The Front Range railway plan is in flux but calls for passenger service that potentially would start as far north as Cheyenne, Wyoming, and go as far south as Pueblo or Trinidad, eventually linking with Amtrak’s Southwest Chief.Last week, Amtrak officials expressed strong support for the regional line and said they would work to help pay for it. Costs for an initial route have been estimated at $2 billion or more, making use of existing freight rail corridors, with a full buildout costing as much as $14 billion. State legislators are considering a bill that would create a Front Range Passenger Rail District in all or parts of 13 counties to oversee the effort.
Front range passenger rail is cool, but it doesn't makes much economic sense.
U.S. prisons were especially susceptible to COVID-19 infection and death; however, data limitations have precluded a national accounting of prison mortality (including but not limited to COVID-19 mortality) during the pandemic. Our analysis of mortality data collected from public records requests (supplemented with publicly available data) from 48 Departments of Corrections provides the most comprehensive understanding to date of in-custody mortality during 2020.
We find that total mortality increased by 77% in 2020 relative to 2019, corresponding to 3.4 times the mortality increase in the general population, and that mortality in prisons increased across all age groups (49 and under, 50 to 64, and 65 and older). COVID-19 was the primary driver for increases in mortality due to natural causes; some states also experienced substantial increases due to unnatural causes.
These findings provide critical information about the pandemic’s toll on some of the country’s most vulnerable individuals while underscoring the need for data transparency and standardized reporting in carceral settings.
Across 49 DOCs (including 47 states, the Federal BOP, and Washington, D.C.), the number of people who died in U.S. prisons was substantially higher in 2020 (6088 deaths) than in 2019 (4206 deaths). This comparison of total deaths does not account for changing custody populations, which decreased during the 2020 pandemic; therefore, rates of in-custody deaths were even higher in 2020. For DOCs with information about manner of death in 2020 (N = 41 DOCs, N = 5134 deaths), 4118 deaths (80%) were due to natural causes, 534 deaths (10%) were due to unnatural causes, and 482 deaths (9%) were due to unknown causes. For DOCs with information about COVID-19–related deaths (N = 19 states, N = 1714 total deaths), 496 deaths (29%) were related to COVID-19.
Techies are obsessed with Cybertruck's 48 volt architecture. 12 volt has been the standard for over 50 years, though a 1965 VW bug actually had a 6 volt system. . . .The reality is that the car industry has been moving toward 48V for the last decade. But it's a difficult transition. Part of the reason is that we've moved from MECHANICAL linkages to ELECTRONIC. Things like the air conditioner, power steering, and power brakes tapped into the main engine mechnically. Power brakes, for example, were powered by the vacuum generatedby the engine. Even the original Tesla Model S didn't have electronic brakes -- it had an electronic device generate a vaccuum, which then powered normal brakes.Nowadays, everything is electronic, not just in electric cars, but in traditional gasoline cars as well. Lower voltage means power needs to be delivered by thicker copper cables, which now becomes a major expense for the car, as well as an extra hundred pounds of weight to carry around.Increasing the DC voltage to 48V from 12V reduces the the copper thickness by exactly 4 (Ohms Law), reducing the cost and weight of copper by 75%.Specifically, one of the things driving the change is "Power over Ethernet". I know what you are thinking, WTF is Ethernet doing in a car???Here's the deal. There are cameras throughout the car now that need to send hi-def video from the edges of the car to the central computer. This far exceeds the bandwidth of old technologies so they are using gigabite Ethernet these days. They've developed a special wiring standard that needs only a single pair of copper wires for both transmit and receive ("Single Pair Ethernet"). They've also developed enough technology to use that same pair to transmit power. These cameras use several watts of power, so would otherwise need additional cables for power. Single-pair Ethernet carrying power thus solves a ton of requirements for car makers. The desired voltage of such systems is 48 volts.The same revolution is happening for consumers, by the way. The USB C Power Delivery standard maxes out at 48 volts when you try to power your laptop at 240 watts. Power = volts times current, and USB cables support a maximum of 5 amps of current.48 volts is where government regulators have decided that DC electronics are "safe" from electrocuting people. Getting much beyond that introduces a whole new level of government interference and regulations.Thus, 48 volts is probably going to be the standard for cars, Ethernet, and USB for the next hundred years.Tesla's Cybertruck is making the jump early. . . . it's likely going to result in a lot of recalls as Tesla makes fixes. But that's okay for a low-volume, new product. What Tesla doesn't want is to change to 48 volts in a Model Y and suddenly have to do a recall of a million vehicles. Cybertruck is a good test platforms to get it working. Presumably, we'll next see it in the higher end Models S/X, and then eventually in the Models 3/Y.
We study the effect of legalization of same-sex marriage on coming out in the United States. We overcome data limitations by inferring coming out decisions through a revealed preference mechanism. We exploit data on enrollment in seminary studies for the Catholic priesthood, hypothesizing that Catholic priests’ vow of celibacy may lead gay men to self-select as a way to avoid a heterosexual lifestyle. Using a differences-in-differences design that exploits variation in the timing of legalization across states, we find that city-level enrollment in priestly studies fell by about 15% exclusively in states adopting the reform. The celibacy norm appears to be driving our results, since we find no effect on enrollment in deacon or lay ministry studies that do not require celibacy. We also find that coming out decisions, as inferred through enrollment in priestly studies, are primarily affected by the presence of gay communities and by prevailing social attitudes toward gays. We explain our findings with a stylized model of lifestyle choice.
* Firetrucks should have lead blankets to assist in dealing with radioactive materials.
* Humans are gradually becoming like Tolkien's elves, long lived, with few children, and high cultural development. Unlike many other technologies based upon physics which are nearing their theoretical limits, medical technology and biotech has immense potential without hitting any hard scientific barriers. We already know all of the physical laws pertinent to biology and chemistry more or less exactly We have proof of concept and possibility in various existing plants and animals. We have increasingly solid understandings of many diseases, of genetics, of biochemistry and anatomy, and of the aging process itself. We have the power to remake ourselves in almost any image we imagine.
* We are fast approaching peak human population, and have the potential to gradually reduce the globe's population without coercion and in the process increase the amount of natural resources per capita while becoming more efficient so we need fewer natural resources per capita.
* Seattle has lots of roundabouts and narrow city streets. More intriguing is why it has so many independent small businesses. Its diversity and large share of immigrants come to mind. Its downtown architecture, on the other hand, is dismal. Liquor in grocery stores is nice. Its high level of environmental consciousness and traffic safety measures are probably good on balance, but inconvenient. It seems to be doing a decent job of infill development.
* Cultures of honor are outdated in the modern world, unless it backslides. Christianity with its doctrine of forgiveness was a way to end blood feuds and get past cultures of honor to a more adaptive society. But we may be backsliding, if civilization can't work well enough.
* Imagine how utopian the world could be without dogs and without guns.
It is generally agreed upon that most individuals who acquire a college degree do so in their early 20s. Despite this consensus, we show that in the US from the 1930 birth cohort onwards a large fraction – around 20% – of college graduates obtained their degree after age 30. We explore the implications of this phenomenon.
First, we show that these so-called late bloomers have significantly contributed to the narrowing of gender and racial gaps in the college share, despite the general widening of the racial gap.
Second, late bloomers are responsible for more than half of the increase in the aggregate college share from 1960 onwards.
Finally, we show that the returns to having a college degree vary depending on the age at graduation. Ignoring the existence of late bloomers therefore leads to a significant underestimation of the returns to college education for those finishing college in their early 20s.
What do liberals not understand about Trump supporters?What liberals may not understand is that Trump supporters do feel that he did something for them. He didn’t help them financially at all, in fact he hurt them with his idiotic policies. He didn’t provide any services for them; exactly the opposite - he cut funding for any service that would help them. He didn’t ‘solve’ immigration, because he had no clue how to deal with immigrants in any intelligent, useful way. He didn’t ‘represent’ them, because he is actually disgusted by them; they were and are only a tool, a means of getting votes from the gullible.But what he did do was legitimize their racism, their hatred for brown immigrants, their hatred for and abject fear of anyone who didn’t look, sound, or act exactly like they did. He legitimized their evangelunacy, even though he has never read a bible in his life. He legitimized their hatred of progress by attempting to roll back each and every intelligent measure made by the previous government. He legitimized their hatred of women being equal to men. He legitimized their hatred of the LGBTQ. That’s all it took - legitimizing their hatred of change and of ‘other.’
Over the years much ink has been spilled defining, explaining, and critiquing standards of review. Countless lawyers, judges, and scholars have flyspecked distinctions among questions of law, fact, and discretion in an effort to derive a coherent theory explaining when and whether appellate judges should endeavor to correct trial court error. Most of these theories have been premised on the notion that standards of appellate review, although sometimes ill-defined, are applied based on consistent legal or rational standards. Our research, however, supports those scholars who posit that standards of review are often influenced by extraneous factors not anchored in a coherent legal conception of deference.
We observe that across a broad spectrum of cases, different panels of jurists apply standards of review in a disparate manner, influenced by their personal backgrounds. Our research explores numerous aspects of personal background, including prior professional legal experience, length of time on the trial court, gender, and political affiliation. Among these categories, we discovered that only one exhibited a statistically significant impact on the selection and application of the standard of review: the type of prior professional legal experience of panelists. Specifically, we find that the criminal or civil practice background of jurists on a reviewing panel influences ultimate outcomes but also shapes the selection of the standard of review.
Based on our findings, we hypothesize that the collective training and experience of a panel in civil or criminal law significantly shapes their analogic reasoning, i.e., their mental model. Consequently, this background factor exerts more influence than others in determining how and when jurists defer to the trial court.
“Civil law only” background panels are most likely overall to apply the de novo standard of review, meaning they are least likely to afford deference to trial court decisions even where they would have the option to do so when considering “dynamic issues.”
“Criminal law only” panels are least likely overall to review for abuse of discretion, and in reviewing criminal cases are most likely to review for substantial evidence.
“Other background” panels are, overall, most likely to review for abuse of discretion and least likely to review issues de novo; they are also least likely of all panels to reverse issues.
Footnote 71 of the paper defines these categories:
We define “criminal law only” background to mean that while in law practice, and before taking the bench, a justice practiced criminal law only and did not report any experience practicing any form of civil law.
We define “civil law only” background to mean that while in law practice, and before taking the bench, a justice practiced civil law only and did not report any experience practicing criminal law. Civil law, for this purpose, includes all non-criminal law, including but not limited to general civil law, probate, family, and transactional law.
We define “other background” such that it includes a mixture of both civil and criminal law practice experience and also nontraditional practice experience that cannot be fairly classified as either civil or criminal law, e.g., law professor.
A panel classified as having a “majority” of “criminal law only” panelists will consist of at least two members who have a criminal law only background. A panel classified as having a “majority” of “civil law only” panelists will consist of at least two members who have a civil law only background.
We provide a lower-bound estimate of the undetected share of corporate fraud. To identify the hidden part of the “iceberg,” we exploit Arthur Andersen’s demise, which triggered added scrutiny on Arthur Andersen’s former clients and thereby increased the detection likelihood of preexisting frauds.
Our evidence suggests that in normal times only one-third of corporate frauds are detected. We estimate that on average 10% of large publicly traded firms are committing securities fraud every year, with a 95% confidence interval of 7%-14%. Combining fraud pervasiveness with existing estimates of the costs of detected and undetected fraud, we estimate that corporate fraud destroys 1.6% of equity value each year, equal to $830 billion in 2021.
This picture isn't real. It's an AI imagined future cruise-ship/floating city.
But, the possibility that this picture depicts is vastly more technologically viable and affordable than housing the same people in orbit, or on the Moon, let alone a more distant planet or moon.
Until the oceans (on the surface and beneath them), the Sahara, the Australian outback, Siberia, Arctic Canada, the American Great Basin, Tibet, and other thinly inhabited places on Earth's surface, are teaming with people, all of which can be done more affordably and with far less ambitious technology than housing the same people in orbit, or on the Moon, colonizing space doesn't make economic sense.
In 2021, an estimated 11.5% (28.3 million) of U.S. adults currently smoked cigarettes.
The average adult cigarette smoker in the U.S. smokes about 6,131 cigarettes a year (about 17 cigarettes a day, a little less than a full pack of 20 cigarettes each day). So, the typical American cigarette smoker is a pack a day smoker. In Colorado, a pack of cigarettes costs $7.99 on average.
Many groups and causes are given perks and preferences, some governmental, and some in business practices. Many don't deserve them.
1. Senior citizens are often targeted for tax breaks and other perks on the theory that they are poor. But, they are the most most affluent age demographic with the lowest poverty rate. They have Social Security, Medicare, and Medicaid nursing home assistance for those who are not upper middle class or more affluent They don't need more.
2. Legacies in college admissions. Our nation was founded on the idea of stamping out hereditary privilege.
3. People who inherit wealth. People who did nothing to earn it shouldn't get tax breaks. Also, our nation was founded on the idea of stamping out hereditary privilege.
4. Clergy.
5. Religion and the religious people.
6. Veterans who were not disabled in their service. They voluntarily made a choice in exchange for promised benefits. We should keep our promises to them. But we don't owe them more than that.
7. Small businesses. Big business should not be placed at a disadvantage vis-a-vis small business. There is nothing virtuous about being a small business and generally small businesses are small because they are not as good as what they do as big businesses, otherwise they would quickly become big businesses.
8. Farmers. Most farmers are wildly inefficient and continue to farm only because the activity is subsidized.
9. Local businesses and farmers and products. Our prosperity and lifestyle is founded upon long distance commerce, not upon buying local or making your own food or goods.
10. Domestic businesses and domestic products. Our prosperity and lifestyle is founded upon international trade.
11. Law enforcement.
12. People claiming to be aggrieved solely because their property values are harmed by something.
The path to holding power was always going to be rocky for the Democrats’ current 51-seat majority, with or without Mr. Manchin.Two incumbents are running for re-election in red states, Montana and Ohio. A third senator, Kyrsten Sinema of Arizona, who was elected as a Democrat but has since switched her party affiliation to independent, has yet to declare her plans — leaving open the prospect of an unusually competitive three-way race. And the party must also defend four Senate seats in four of the most contested presidential battlegrounds: Wisconsin, Nevada, Pennsylvania and Michigan. . . .Democrats must win every race they are defending — and depend on President Biden to win the White House — in order to maintain a majority. In a 50-50 Senate, the vice president casts the tiebreaking vote. . . .The bad news for Senate Democrats is that they are on defense in each of the seven seats that both parties view as most competitive this year. The good news is that in five of those seven, the party has incumbents running for re-election, which has historically been a huge advantage.At least 83 percent of Senate incumbents have won re-election in 18 of the past 21 election cycles, according to OpenSecrets, a nonpartisan group that tracks money in politics. Last year, 100 percent of Senate incumbents were re-elected. . . .The Democratic incumbents in Montana and Ohio . . . are seeking re-election in states former President Donald J. Trump easily won twice. Both Senator Jon Tester of Montana and Senator Sherrod Brown of Ohio have exceeded expectations before, but never with such an unpopular presidential candidate at the top of the ticket. And unlike most incumbents, whose victories tend to become easier over time, Mr. Tester has always had close races. Mr. Brown’s margins have narrowed. . . . Democrats maintain that the personal brands of both Mr. Brown and Mr. Tester matter more in their states than national political winds. . . .The most interesting of the second-tier races may be in Arizona, where the state may have a competitive three-way race — a rarity in American politics. The wild-card is Ms. Sinema. If she runs for a second term, she will most likely face Representative Ruben Gallego, a well-liked progressive Democrat who has already spent $6.2 million on the race this year, and Kari Lake, the firebrand conservative Republican and one of her party’s best-known election deniers who is favored in her party’s primary. . . .There is no top-flight Republican challenging Senator Tammy Baldwin in Wisconsin, but the party has been pushing for Eric Hovde, a businessman who ran for Senate in 2012.
In Pennsylvania, Republicans have cleared a path for David McCormick with the aim of avoiding a bruising primary and strengthening their bid against Senator Bob Casey, who is seeking a fourth six-year term. . . .
In Michigan — the only competitive Senate race without an incumbent — Democrats so far have mostly aligned behind Representative Elissa Slotkin, a former C.I.A. analyst who represents a divided district. Mr. Daines recruited former Representative Mike Rogers, who was chairman of the House Intelligence Committee. But James Craig, a former Detroit police chief, and former Representative Peter Meijer, who lost his seat after voting to impeach Mr. Trump, have also entered the Republican race.The Republican establishment pick in Nevada is Sam Brown, a retired Army captain who lost a Senate primary last year. But he’s facing a primary against Jim Marchant, a Trump loyalist and election denier who lost a race for secretary of state last year. The winner would take on Senator Jacky Rosen, a Democrat who is seeking her second term. . . .In Florida, Senator Rick Scott, the state’s former governor, is seeking a second term. He’s never won an election by more than 1.2 percentage points, and he’s also never run in a presidential election year — when Democrats typically fare better in Florida. But the state lurched to the right last year when Republicans won five statewide races on the ballot by an average of 18.9 percentage points. The leading Democratic challenger in the Florida Senate race this year is former Representative Debbie Mucarsel-Powell, who was unseated from her Miami-based seat after one term.In Texas, Senator Ted Cruz has been a constant target for Democrats — and survived each time. This year, his top challenger appears to be Representative Colin Allred, a Dallas-area Democrat who defeated an incumbent Republican in 2018.
This post restates an answer I made at Politics.SE where I am a moderator and participant, with only one minor modification to remove a reference to another answer at the site, adding a link, adding some discussion of the situation in Alaska, making minimal formatting modifications, and quoting a comment to the answer. I quote the question I am answering piecemeal during the answer.
In the course of answering this question, I was surprised to learn just how undivided and not gridlocked the state political process in the United States has become, in stark contrast to the federal political process in the United States.
What kind of amendment clause can encourage many parties to represent the voters in the way originally intended by the founding fathers?
What kind of amendment can oblige multiple political parties, to fix the unintended two-party malfunction of the constitution?
In each State entitled in the Ninety-first Congress or in any subsequent Congress thereafter to more than one Representative under an apportionment made pursuant to the provisions of section 2a(a) of this title, there shall be established by law a number of districts equal to the number of Representatives to which such State is so entitled, and Representatives shall be elected only from districts so established, no district to elect more than one Representative (except that a State which is entitled to more than one Representative and which has in all previous elections elected its Representatives at Large may elect its Representatives at Large to the Ninety-first Congress).
The founding fathers did not foresee that the constitution would foster a two-party political system that is radical, inflexible and deadlocked. There is probably little political will to reform it for many reasons, at the cost of prosperity, security, efficiency and peace.
The U.S. federal government is undoubtedly very prone to deadlock. A majority of representatives in the U.S. House, a large minority of U.S. Senators, the President, or the courts applying constitutional rules that invalidate federal laws, each have de facto veto power over new legislation. And, the power of the two major political parties in the U.S. is equally balanced.
One of the other well known political science laws is that in a two party system (or generalizing it, to a two coalition of parties system), where the parties (or coalitions) are ideologically coherent are prone to continually attempt to tweak the composition of their pre-election coalitions by changing their policies or political tactics, in a way that tends to bring them close to a 50-50 balance of power in the governmental institutions that they most strongly wish to control (the federal government in the U.S. case).
The U.S. federal level political system has been quite evenly balanced between the two major political parties for most of the period since the 1980s (more than four decades) with only brief periods when a single party had "trifecta" control of both houses of Congress and the Presidency, and courts that have been disinclined to thwart their agenda.
In contrast, during the Great Depression and into World War II, the federal government was a dominant party system united under FDR's Democratic Party, and the initially combative Lochner era U.S. Supreme Court eventually backed down when faced with court packing legislation that was likely to pass.
Also, the most recent Congressional elections in 2022 produced outcomes in terms of legislative seats held in the U.S. House that quite closely tracked the overall popular vote for each political party nationwide, with factors that favored Republicans in some places balanced by factors that favored Democrats in other, ultimately balancing out for the nation as a whole. And, the increased partisanship and ideological distance between the political parties seen in Congress mirrors increased partisanship and ideological distance between the political parties in the electorate itself.
Legislation that has bipartisan support (e.g. aid to Israel in the wake of recent events there) can still get passed. But it has been the exception rather than the norm pretty much since the 1980s (before which there was a short period when the Democratic party was dominant at the federal level) that a single party without bipartisan support can pass federal legislation leading to major policy changes. These windows of opportunity have appeared now and then and been utilized by the parties having them. But these windows of opportunity have generally been short-lived and resulted in only moderate and somewhat incremental, rather than decisive and bold reforms.
Arguably, a system that produces gridlock and little federal legislative activity in time periods when the nation is deeply and fairly evenly divided on most political issues, is exactly what the Founders intended when they created a federal political system. When the nation is united, major new national political policies can be enacted, but when the nation is divided, real major policy innovations become much easier to achieve at the state and local level than they are to achieve at the federal level.
The two party system doesn't necessarily have a lot to do with that. Ultimately, exercising political power to change the status quo is about securing legislative majorities to take action, which requires majority support from legislators as measured by the standards of the political system to pass legislation.
In a two party political system, one assembles coalitions that the organizers of the respective political parties hope will be sufficient to secure the majorities necessary to pass legislation before the election into two pre-negotiated coalitions.
In a multi-party political system, coalitions that their member political parties hope will be sufficient to secure the majorities necessary to pass legislation are negotiated after the election.
Lots of countries, especially non-federal "unitary" political systems, make it easier to secure a legislative majority than the U.S. does. But, it isn't manifestly obvious that the task of organizing a multi-party coalition (probably balanced close to 50-50 anyway) with sufficient backing to pass legislation after Congressional elections are held would have an easier time passing legislation than the task of building one of the two major party coalitions before the election to achieve this goal in the status quo.
Also, countries with these unitary systems where the majority threshold needed to pass legislation is lower are often more politically homogeneous than the United States is politically. This lack of political consensus at a national level was a fact that was apparent even back in the time when the Founders set up the current U.S. Constitution, and it shaped how the U.S. Constitution was written.
Federal level political gridlock is ugly and frustrating.
But political gridlock is not the norm in most U.S. states, despite the fact that they also have two party political systems, mostly because most U.S. states aren't so evenly politically divided and secondarily because most U.S. states have fewer barriers to legislating (like the minority veto powers created by U.S. Senate rules and unequal populations for U.S. Senate electoral districts, i.e. U.S. states).
"not in the interest of either of the two major political parties" In the simplest case where no new parties get founded and actual voters' votes remain the same, PR would have denied the Republicans a majority in the House in 1996, 1998, 2000, 2004, 2012, and 2016; but there has been no case since the present system was introduced when the Dems won a majority under the present system but would have been denied it under PR. Hence, PR could be argued to be in the Dems' interest. – Daniel Hatton
