The authors of the coup attempt remain embedded in the Republican Party and in the conservative movement. Some are officeholders, like Representative Marjorie Taylor-Greene of Georgia, while others continue profitable associations with institutions ranging from the New Civil Liberties Alliance, a right-leaning public-interest litigation group, to Fox News and other media outfits.

The Trump administration was grotesque in its cruelty and incompetence. But without the coup attempt, it might have been possible to work out a modus vivendi between anti-Trump conservatives and Mr. Trump’s right-wing nationalist-populists. Conservatives were not happy with Mr. Trump’s histrionics, but many were reasonably satisfied with all those Federalist Society judges and his signature on Paul Ryan’s tax bill. Trump supporters, who were interested almost exclusively in theater, enjoyed four years of Twitter-enabled catharsis even as the administration did very little on key issues like trade and immigration.

In the normal course of democratic politics, people who disagree about one issue can work together when they agree about another. We can fight over taxes or trade policy.

But there isn’t really any middle ground on overthrowing the government. And that is what Mr. Trump and his allies were up to in 2020, through both violent and nonviolent means — and continue to be up to today.