With an explosive interview to the New York Times that dominated national headlines on Monday, Republican Senator Bob Corker of Tennessee unleashed on his party’s leader as he accused President Donald Trump of treating his office like “a reality show” and said his reckless behavior could lead to World War III. 

“He concerns me,” Corker said of the president. “He would have to concern anyone who cares about our nation.”

On Sunday, in response to attacks by Trump on Twitter, Corker said the White House has “become an adult daycare center”:

Chair of the powerful Senate Foreign Relations Committee, Corker’s unease with the president is partly related to recent saber-rattling against North Korea and Trump’s undermining of diplomatic efforts by Secretary of State Rex Tillerson.

“A lot of people think that there is some kind of ‘good cop, bad cop’ act underway, but that’s just not true,” Corker said.

The feud between Corker, who recently announced he will not seek re-election in 2018, and Trump has been growing steadily over days, but one of the most telling revelations from the interview is Corker’s claim that most of his congressional colleagues feel the same way, even though few, if any, have been so scathing in voicing their concerns about the president in public.

“Look, except for a few people, the vast majority of our caucus understands what we’re dealing with here,” he said, adding that “of course they understand the volatility that we’re dealing with and the tremendous amount of work that it takes by people around him to keep him in the middle of the road.”