Why did the Democrats cave in on the shut down? It seems clear that the main issue was not electoral backlash, since most of the senators who caved are not up for reelection, and the politics were trending in the Democrats’ favor, or at least not against them.

The main issue was the filibuster. There was growing pressure from Trump on the Republicans to get rid of it, and the Democratic leadership had every reason to fear its elimination. Why?

It has very little to do with preserving their power while they are in the minority; that ship has obviously sailed.

The Democratic leadership doesn’t want to get rid of the filibuster for the same reason the Republican leadership doesn’t want to get rid of it: The filibuster allows the leadership of both parties to keep their radical flanks at bay. Schumer needs the filibuster to protect himself from the Sanders wing in the Senate and the AOC wing in the House: if you can’t get to 60, Bernie and AOC, we gotta follow the lead of Joe Manchin and Kyrsten Sinema. Same goes for John Thune to whoever inhabits the radical role at any given moment in the GOP.

You have to read the media coverage on this issue carefully. Usually, the blah blah blah of filibuster reportage is about the party worrying what happens when it is in the minority or individual senators worrying about losing their individual power. That’s the buzz of Broderism, a style of reporting that’s a holdover from the last century.

The real moment of truth comes in a nugget like this, from an article in the Times on November 4, which got lost amid the excitement about the Mamdani election:

In reality, the filibuster also serves Republicans as a handy check on a president who sometimes takes stances that carry substantial risk or defy party orthodoxy, an excuse for Senate Republicans to avoid doing things they don’t see as sound policy or politics without infuriating Mr. Trump.

For Trump, swap in Trump’s most rabid allies and foot soldiers in the Senate and the House—or Schumer’s and Jeffries’s enemies in the Senate and the House—and you get a pretty clear sense of why the leaderships of both parties need the filibuster: It checks anyone who “defies party orthodoxy,” while providing “an excuse to avoid doing things.”