The second way the filibuster could fall is far worse for Democrats: Republicans could regain full control of Washington and decide that the 60-vote threshold has outlived its usefulness. The last time the GOP held the House, White House, and Senate, in 2017, Republicans ignored President Donald Trump’s repeated calls to end the legislative filibuster. But if they regain control of Washington in 2024, the situation will be very different. Any newly elected Republican senators will belong to a party in which fealty to Trump—a filibuster opponent—is the most important plank. And even their long-serving colleagues may decide that, in a body governed mostly by precedent, Democrats have set a new one. Mitch McConnell or his successor can point to dozens of recent statements and speeches by their colleagues across the aisle arguing that the filibuster either should be ended entirely or ignored when a sufficiently crucial bill demands it.

This is especially true if Trump, or a Trumplike president, wants to rig elections nationwide. The overwhelming majority of Senate Democrats are now on the record articulating a principle: Protecting voting is an important enough priority that it is worth going around the filibuster in order to advance it. The same principle, repurposed under Donald Trump’s misleading definition of “election integrity,” could be used by Republicans to justify nationwide anti-voting laws as well. (Such arguments would be, of course, in bad faith. But that won’t prevent anyone from making them.)