Under President Barack Obama, Americans saw how divided government leads to crisis-wracked governance, with the Republican Congress roadblocking presidential appointments (particularly in the courts) and playing a game of chicken with the debt ceiling that risked sending the country into default. Now, under President Donald Trump, Americans are seeing that unitary government also leads to crisis-wracked governance, with the Republican Congress unable to coalesce around an agenda.

“We’re getting nothing done,” Senator John McCain lamented in a much-discussed speech on Tuesday. “All we’ve really done this year is confirm Neil Gorsuch to the Supreme Court.” Two days later, in the dead of night, the Republican from Arizona cast the key “no” vote that sunk the Senate Republican’s hurried, not-at-all-skinny legislation to repeal Obamacare, an incoherent shell of a bill that didn’t even satisfy Republicans’ ideological demands. Some 16 million Americans were one “yes” away from losing health insurance, all because a ruling party in disarray was desperate for a win. In a statement explaining his vote, McCain said, “We must now return to the correct way of legislating.”

McCain’s plea is certain to be ignored by his colleagues—and may not even be heeded by McCain himself. That’s how broken Washington’s politics have become.

If there is gridlock and chaos under both divided and unitary government, that suggests the problem is systemic rather than being caused by a particular partisan alignment. Trump himself seems to recognize this. Saturday morning, he went on a Twitter tirade about the need to get rid of the filibuster. “The very outdated filibuster rule must go,” Trump wrote. “Budget reconciliation is killing R’s in Senate. Mitch M, go to 51 Votes NOW and WIN. IT’S TIME!” Trump is half-right, or perhaps a quarter-right. Getting rid of the filibuster would improve American democracy if it were combined with other reforms.

America is a presidential republic that functions best when the political parties are ideologically broad. That is increasingly untrue as the Republicans and Democrats have, in different ways, begun acting in a parliamentary fashion, with a high degree of political cohesion within their ranks. The main difference is that the Democrats have cohered around shared policy goals, like protecting and expanding the safety net, while Republicans have cohered around negative partisanship—that is, their opposition to the Democrats. But whatever the reason, there’s no dispute that the two major parties have become more polarized than ever.

