Somehow, despite divided control of both the Colorado General Assembly and Congress, both Colorado and the Congress managed to approve budgets this month. This is what usually happens, even in times of divided government. It doesn't happen without fail. There have been a number of government shutdowns, although the longest one at the federal government level was twenty days, and most haven't been longer than a day or two.
The process does nothing to guarantee that a compromise is reached. No majority can single handedly impose its will. But, time and time again, deals are struck. Much of the time, government is not divided and the deals aren't so difficult to secure. But, even in the time periods when government is divided, there is usually a deal.
Most business deals work on the same basis as budget deals. Everything is decided on a quite short scale, or nothing is decided. Juries likewise resolve disagreements by consensus. Miraculously, when the choice is no deal, no budget, no verdict . . . most of the time deals are secured. There are frequently compromises, but deals are secured.
Courts determine the status quo in the absence of a deal. Most of the time, there is a sensible or at least workable alternative if a deal on legislation falls apart. If there is a deadlock in a redistricting matter, usually courts will intervene and draw a map themselves. But, this rarely happens with the budget. If no deal is reached, the money will not be spent. The budget is "must pass" legislation. Sometimes there are compromises for "essential services" if the rest of the government is shut down. But, those are usually handled outside the courts.
A functioning government that spends money on government services, when push comes to shove, is a better outcome than one that does not function.
Federalism lowers the stakes. One of the key benefits of federalism is that even in a system that sometimes produces government shutdowns from political impasses, the entire government isn't affected at once. Only a few states in any given year will reach an impass on their budgets, and they won't do so all at once. Local governments are not directly shut down by impasses at the state level. Federal government shutdowns still leave the state and local governments that employ the vast majority of government employees, any agencies whose appropriations bills managed to pass before there was an impass, and self-funding agencies like the postal service in business.
I'm a pessimist on this score. I worry about system failure. I worry about a prolonged failure to the political system to meet its basic responsibilities. We haven't had serious steps across that line in the United States. But, in other countries there have been long periods, many months or even years, of deadlock. The labor-management equivalent - a long strike or lockout due to failure to reach a deal - used to be much more common. Usually, those dire worst case scenarios don't happen. But, it takes more than Civics 101 and Constitutional law to explain what goes on when these miraculous agreements happen. A shallow analysis of the rules of our political system can't easily explain why negotiations break down so much less often than one might expect that they would, what is different about the times when they do break down, why the breakdowns are more or less intractable in different situations, and as a result, also can't explain how fundamentally stable our system of government that depends upon partisans who disagree compromisings in unspecified ways is within a coherent theoretical context. We have a good track record of compromise so far, but why?