Democrats Caved in the Shutdown Because of the Filibuster
For Democrats, the main issue in the shutdown wasn’t electoral backlash — it was the filibuster. Leadership feared its removal, viewing it as a safeguard to keep the party’s rising left wing in check.

The leadership of the Democratic Party wanted to preserve the filibuster for one reason: it checks anyone who defies party orthodoxy.(Daniel Heuer / Bloomberg via Getty Images
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 Donald 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.