Dissembling is not a crime, but doing so to conceal a wholesale reversal on a matter as serious as an attack on the citadel of democracy and the possible resignation of a president would once have been considered career-ending for a politician, particularly one who aspires to the highest position in the House.

Not so for a Republican in the age of Trump, when Mr. McCarthy’s brand of lie was nothing particularly new; maybe it was just a Thursday. On Friday, another House member, Representative Marjorie Taylor Greene, Republican of Georgia, said under oath at an administrative law hearing in Atlanta that she could “not recall” having advocated Mr. Trump imposing martial law to stop the transfer of power to Joseph R. Biden Jr., a position that would seem difficult to forget.

“It’s a tragic indictment of the political process these days — and the Republican Party of late — that truth doesn’t matter, words don’t matter, everybody can be elastic in areas that were once viewed as concrete,” said Mark Sanford, a former Republican governor of South Carolina who lied to the public about his whereabouts when he was pursuing an extramarital affair in South America and was censured by the State House of Representatives. “You cross lines now, and there are no longer consequences.”