Nicholas Lemann’s “The Republican Identity Crisis After Trump” explores what will happen to the movement Donald Trump created among Republicans. In his 2016 campaign, he ran as a populist insurgent against Wall Street, “élites,” and the Republican Party itself—mobilizing voters against their traditional leadership. But, in office, he has governed largely according to the Party’s priorities. If Trump loses next month’s election, what will become of the movement he created? Lemann spoke with David Remnick about three possible scenarios for Republicans.