Some progressives seem to think that’s fine. They’re voting like Republicans anyway, right? But chasing the two senators out of the party at this moment would be hugely costly to Democrats.

Among the repercussions: Republicans would be given a fresh tool to block the confirmation of presidential appointees. Thanks to a relatively recent carve-out from the filibuster, such appointees — the folks who do the day-to-day work of managing government agencies like the Environmental Protection Agency and the Justice Department — can pass through the Senate on a simple majority vote. The GOP already uses procedural rules to hinder Biden’s nominees from taking office; just imagine what they’d do with a Senate majority? If Democrats lose control of the Senate, Biden’s White House will be hobbled as well.

More consequentially, handing control of the Senate to Republicans would probably all but end the flow of Biden’s judicial appointments. He got 42 nominees appointed to federal judgeships during his first year in office — the highest number since Ronald Reagan — thanks to the other exception to the filibuster. Forfeiting additional opportunities would be a terrible self-own for Democrats. So would giving up the possibility of filling up any Supreme Court vacancies in the near future. Fixing the high court will already be the work of generations for liberals; they shouldn’t start on that task by digging the hole deeper.