The bills McConnell is threatening—like immigration crackdowns or abortion restrictions—are ones that will both rile up the GOP base and make some Democrats queasy. They’re also precisely the ones that would have the weakest support from the vulnerable GOP senators their majority is all but certain to depend upon. Senators at risk of losing their seats won’t want to upset their fragile electoral security by taking a recorded vote that may trigger voter backlash, and the party won’t want to jeopardize their majority status by forcing them to do so.

Party leaders like McConnell know full well that pursuing base-pleasing but nationally unpopular issues can often do the party more harm than good. Remember the Obamacare replacement fiasco the last time the GOP controlled Congress and the White House? Not only did they fail to write a bill that satisfied enough members of their own party despite it being a major campaign pillar, their very public activity on the issue focused voter attention and stimulated subsequent turnout that ultimately cost the GOP their House majority.

This political reality actually underpins a major counterintuitive reason the filibuster has stuck around so long: the filibuster is convenient political cover for the majority party, and particularly its most vulnerable members.