I'm a "Fox" and not a "Hedgehog". I know many things and focus on details rather than "one big thing" that solves every problem.
But, I'm going to try to put on my hedgehog hat and come up with ways to address some of the biggest problems facing the U.S. today if forced to suggest just three solutions to each of them. The point of this exercise is partially to force prioritization of lists of proposals that can get bogged down with good ideas to solve small problems or to make lower priority reforms to big problems.
Affordable Housing and Homelessness
Housing prices in major metropolitan areas are high. What is the single biggest thing we can do to address that?
Eliminate virtually all zoning regulations of residential density, parking requirements, minimum lot sizes, and regulation of the purposes for which buildings can be used. This primarily reduces the land value part of housing costs which is the main factor that makes housing in big cities so much more expensive.
What is another big thing that we can do to address that?
End all property tax funding of public schools and replace the lost revenue, dollar for dollar, with increased state income taxes. This will typically reduce property taxes by more than 50% freeing up income for making principal and interest payments. It would also reduce inequities in school funding and would be more progressive as a tax source.
What is a third big thing we can do to address that?
Spend whatever it takes to provide basic housing first, immediately, to every single homeless person in the United States. Housing first is cheaper than letting people live on the street and paying the costs of that. This is less burdensome on the health care system, reduces crime, and improves quality of life for both the people who would be homeless and the people that their being homeless in their neighborhoods would impact.
Health Care
The U.S. pays far more per person for healthcare than any other country on the planet and gets poor results for its money, while inflicting great financial hardship on people. What is the single biggest thing we can do to address that?
Adopt "Medicare for All" financed with a higher Medicare payroll tax and a higher Obamacare tax on investment income. Roll in long term care coverage currently paid for, for many people, with the Medicaid long term care program.
End Medicaid. End the Medicaid Estate Recovery System (i.e. the poor man's death tax). End private health insurance. End worker's compensation coverage of medical expenses. End the separate veteran's healthcare programs. End Obamacare insurance premium subsidies. End health insurance tax deductions and employer health insurance mandates and private health insurance mandates. End lawsuits by private individuals to pay for medical expenses. End casualty insurance policies designed to cover liability for medical expenses in lawsuits. This would greatly reduce administrative cost waste, bad debt, denial of care, linkage of health care to employment, would reduce health insurance and worker's compensation and CGL insurance expenses for businesses, would simplify tax returns for individuals, and would facilitate more effective cost control on provider payments. It would also increase use of preventative care thereby reducing more expensive acute care and would shift expensive ER care for the currently uninsured to more appropriate lower cost providers. This would especially help working class people who are mostly likely to have inadequate health insurance and to struggle with paying medical bills.
What is another big thing we can do to address that?
Legalize "recreational" drugs in a highly regulated and controlled manner similar to Colorado's marijuana legalization to reduce harm, while providing strong support for substance abuse treatment including drug based therapies and inpatient treatment funded with Medicaid for All resources. This would dramatically reduce the overdose epidemic, and would improve recovery rates for alcoholics and drug addicts, something that takes a particular toll on the poor and working class. This would also dramatically reduce gang crime and organized crime and would cripple cartels, and would reduce crime by addicts and would reduce incarceration costs associated with controlled substance users and jail deaths from drug withdrawal. The reduced demand would also dramatically reduce crime abroad from Columbia to Mexico, which would reduce the flow of refugees and migrants to the U.S. and would reduce corruption in the affected governments.
What is a third big thing we can do to address that?
Double the number of medical student slots for educating physicians by expanding medical school capacity and building new medical schools. We shouldn't have the same number of MD education slots as we did fifty years ago, with twice the population, and there is no shortage of highly qualified premed graduates to fill those slots. Limited supply also drives ups provider costs. Ending student loans for medical students and Medicaid for All ending bad debt issues and administrative costs for self-employed doctors and lowering malpractice insurance coverage due to not having to pay for malpractice related medical bill compensation would also allow reduced MD charges without undue hardship for MDs.
Higher Education
It is very expensive to go to college and many people leave college with large student loans that can't be discharged in bankruptcy. Many kids who are ready for college don't go, but many kids who aren't ready for college go at great expense in public funds and for themselves. What is the single biggest thing we can do to address that?
Provide 100% grant based funding for tuition, room, board, and books to students pursuing higher education whose grades and test scores and other factors show that they have at least a 50% chance of completing the higher educational program that they are enrolled in. Do not fund higher education for people who have a low chance of completing the higher educational program that they are enrolled in. End government sponsored or guaranteed student loans. This would much better utilize our nation's supply of academically competent students while reducing dropouts and failures by people who aren't currently ready for college at great expense and undermining personal self-worth. The status quo of indiscriminate state subsidies to in state students and very low admission thresholds that insure that huge percentages of students admitted at public and for profit colleges drop out without degrees is wasteful while still excluding poor and working class students at high levels from the system. Some of the political alienation towards higher education also comes from people who tried and had bad experiences since they weren't ready and dropped out and from people who were shut out of the system when they were prepared and take a sour grapes attitude towards it.
What is another thing we can do to address that?
Improve apprenticeship systems and vocational education programs, both for high school aged students whose academic performance indicates that traditional liberal education programs in a four year program don't make sense for them, and through community colleges. Adopt occupational specialty identification and training approaches used by the U.S. military for enlisted recruits for civilians. This would provide a path to missing middle occupations and recognize that not going to college doesn't have to mean that there is no path to the American dream.
What is a third big thing we can do to address that?
Forgive all existing federally guaranteed or federally provided student loans, and end the prohibition on discharging student loans in bankruptcy for all other student loans ten years after the repayment period begins if a degree is earned and professional certification is obtained in a pre-professional program, and after five years in all other cases. This would provide intergenerational justice to struggling Millenials and Gen Xers and Gen Z. These students could then better afford the American dream and could better afford to get married and have kids.
Poverty
Lots of people, especially children and single parents, but also many older adults with little education or skills, are poor and struggling. What is the single biggest thing we can do to address that?
Make the large, per child tax credit, that was available during the pandemic, permanent, and replace the complicated and audit prone earned income tax credit with a simple income tax credit equal to Social Security taxes (for both employers and employees) up to the minimum wage times thirty hours a week (or an equivalent amount of credit against self-employment taxes - reflected in not having those taxes withheld. The usefulness of the child tax credit in reducing child poverty in a simple way was demonstrated in the pandemic, and the EITC is far too complicated and has bad incentives for people trying to climb out of low income jobs and is too expensive to administer. This would make it more affordable for Millennials and Gen Z to marry, have kids, and achieve the American Dream.
What is another big thing that we can do to address that?
Reduce the regular Social Security retirement age to 55 years to people who do not have college degrees, without a reduction in benefits, and pay for any shortfalls in social security from existing obligations or new coverage, by increasing the payroll tax cap by however much is necessary to pay for it. Consider this payback for not imposing higher education costs on the public, and well as a rough justice categorical recognition that jobs that require less education are frequently more physically demanding and harder to continue to perform in late middle age. This would particularly help the Trump demographic. Many people in this demographic are already voting with their feet by leaving the work force and often applying for disability benefits which wouldn't be necessary with this categorical benefit that is much cheaper to administer and has better incentives.
What is a third big thing we can do to address that?
Provide paid maternity leave, at public expense, from six months of pregnancy to fifteen months after birth, as a short form, temporary, Social Security disability benefit. Add an additional six months to this time period for twins. Pay for this as well with an increased payroll tax cap. This greatly reduces the need for infant daycare, and increase the health of mothers and babies especially for working class families without unduly burdening employers. The pandemic proved that not being at work in late pregnancy out of economic necessity increases maternal and infant health. This would make it more affordable for Millennials and Gen Z to marry, have kids, and achieve the American Dream.
Transportation
Internal combustion engines are polluting and make up dependent upon oil. What is the single biggest thing we can do to address that?
Reduce trade barriers to importing foreign EVs and batteries, and subsidize high speed charging networks. There are lots of good EVs out there that aren't being exported to the U.S. due to trade barriers, especially from China. EVs reduce pollution and reduce fossil fuel dependency with petroleum dependency creating national security issues.
What is the second biggest thing we can do to address that?
Build dedicated high speed rail in interstate highway corridors where there is high traffic volume on medium distance routes (and upgrade medium speed rail corridors that already exist like the one in the Northeast Corridor), and use that high speed rail not only for passengers but for mail and package delivery by the USPS. Pay for this, in part, by shutting down low speed AMTRAK routes with the heaviest subsidies per passenger-mile. This could reduce pressure to expand highways, is environmentally sound, reduces highway maintenance costs, and provides mutual support between the rail system and the postal system. It would improve speed on these routes relative to both cars and to commercial flights. But it only makes sense where it makes some sort of economic sense based upon cost and demand. Medium distance, high volume routes are the sweet spot for high speed rail. Reducing petroleum dependency in addition to being environmentally and climate sound would increase national security and economic stability by reducing exposure to global oil production shocks.
What is a third big thing we can do to address that?
Convert short haul government fleet vehicles like garbage trucks, intracity and school buses, and urban postal delivery vehicles to EVs. This is a perfect niche for EVs even before charging networks are built out, reducing pollution and reducing oil demand with the benefits described above.