Trump’s shadow hung over this week’s meeting here. Fifteen prominent Republicans who had served in past GOP administrations met Sunday for a private soul-searching session that one attendee described as “painful and empathetic.” The next day, eight of them joined in signing the public declaration by 50 top GOP former national-security officials warning that Trump would be “the most reckless president” in U.S. history.

“We’re seeing a mass exodus of senior and experienced Republicans from Trump on national security. They are deserting him because he has denigrated NATO, appeased [Russian President Vladimir] Putin and shown little faith in American power,” argued Nicholas Burns, director of the Aspen Strategy Group, who served as undersecretary of state under President George W. Bush. Burns had earlier announced that he would support Hillary Clinton for president.

Trump seemed to relish this defection by the establishment. He described the 50 signers of the declaration as “nothing more than the failed Washington elite looking to hold onto their power,” and thanked them “for coming forward so everyone in the country knows who deserves the blame for making the world such a dangerous place.”