Many of those who remain will have to accommodate the president to survive primaries from the pro-Trump right. Already, in the high-profile campaigns of 2017 — governor races in Virginia and New Jersey and a special Senate race in Alabama — Republican candidates are mirroring Mr. Trump’s racially tinged campaign tactics. And Republican officials are putting up with the sort of incendiary candidacy that a party more devoted to nurturing a tolerant image might have rejected.

The reason? Many of their voters prefer the Trump way.

“We’re not an element,” said Laura Ingraham, a pro-Trump talk show host. “We’re the party.”