“You could write the history of the modern Republican Party over the last two years, and what does Jan. 6 look like? A hiccup,” said William Kristol, the neoconservative writer who co-founded Republican Voters Against Trump, a group spending millions of dollars to oppose Trump-backed election deniers. “The price of admission to today’s Republican Party is turning a blind eye to Jan. 6.”

That was the experience of Representative Peter Meijer of Michigan, who voted for Mr. Trump’s impeachment weeks after taking office and lost his re-election primary this month. He said his constituents asked him about his impeachment vote 10 times as much as about anything else.

“Policy is not policy toward improving government,” Mr. Meijer explained. “It’s policy as a signifier of whether you’re part of the in group or the out group.”…

“I can’t tell you the number of times somebody said, ‘You don’t have to believe the election is stolen, the important thing isn’t believing it, it’s saying it,’” Mr. Meijer recalled in an interview. “That is what a Republican is supposed to do right now.”