From Ronald Brownstein, explaining in a nutshell what’s happened to our political system:
We are operating in what amounts to a parliamentary system without majority rule, a formula for futility.
Yep. In a parliamentary system, party discipline is absolute. With a few rare exceptions, you vote with your party at all times, and there’s no such thing as “bipartisanship.” And it works fine. But it works fine because parliamentary democracies have a bunch of machinery that makes it work: majorities are able to pass legislation, no-confidence votes can bring down an unpopular government, party platforms are taken seriously, etc. We don’t have any of that stuff. What we’ve evolved over the past 20 years is a de facto parliamentary system without any of the machinery that makes it work. The result is national gridlock.