Steve Schmidt, who was senior adviser to McCain in the 2008 presidential campaign, says Trump’s GOP rivals and others in the party must step up and confront him. “What he represents has to be taken seriously. It has to be confronted seriously,” he said in a telephone interview. “It’s not just a cancer on the Republican Party and the conservative movement. It’s a cancer on our politics as a whole. . . . My personal view is that it ought to trigger a fight for the soul and heart of the Republican Party and the conservative movement.”

Another prominent GOP strategist, speaking anonymously to be candid, counseled a more nuanced approach. Candidates should prosecute the case against Trump, this strategist said. “But they have to do that with a certain amount of respect, with disappointment in their voice, and not go over the top.”

Trump’s harshest critic among his fellow Republican candidates has been former Texas governor Rick Perry. Even before Saturday’s controversy, Perry had aggressively criticized Trump for his comments on immigration. Now, after the attack on McCain, he says the businessman should get out of the race.