What party leaders have going for them is that the members who could blow up the partisan budget bill really want to pass the bipartisan infrastructure one, and vice versa. As Representative Steny Hoyer of Maryland, the House majority leader, told the Democratic rank-and-file on Monday, “this is mutually assured destruction.”

The analogy is apt. In its original, Cold War context, the term “mutually assured destruction” referred to the understanding that the United States and the Soviet Union each possessed enough nuclear weapons to annihilate the other — and that, therefore, it was in neither country’s best interest to do it, because it would be annihilated, too.

This is not a kingmaker situation in which a small faction capable of tanking legislation extracts concessions in exchange for their votes. That happens all the time. Just look at Senators Joe Manchin III of West Virginia and Kyrsten Sinema of Arizona.

What makes the current situation in the House so unusual — so, well, mutually assuredly destructive — is that each side has leverage over the other at the same time.