The other scenario for Trump has Republicans maintaining their majority, raising questions of who would succeed retiring Speaker Ryan. He is promoting No. 2 House Republican McCarthy. In 2015, McCarthy's first bid for speaker was torpedoed by fractious Republican conservatives.
Trump has a close relationship with McCarthy, a former deli owner. "My Kevin," as Trump sometimes calls him, has offered legislation to fully fund the president's proposed U.S.-Mexico border wall.
But conservative rivals are keeping close watch on whether McCarthy's bid for speaker takes flight. No. 3 House Republican Steve Scalise said he would not challenge McCarthy. But supporters of Scalise, the Louisianan who was shot in 2017 by a lone gunman, have said he would jump in if McCarthy sputters.
Aides to McCarthy did not respond to requests for comment.
Jim Jordan, a leader of the right-wing House Freedom Caucus, has announced his candidacy for speaker, complaining that Republican leaders are too apt to back down from fights with Democrats. Jordan has occasionally opposed some Trump-favored legislation.
Jockeying for the speaker's job will intensify in mid-November as newly elected Republican and Democratic House members prepare to choose respective leaders. In early January, all 435 House members will vote for a speaker.