MSNBC’s Joe Scarborough torched Donald Trump Monday over his “stupid” refusal to condemn the Ku Klux Klan, a move that comes after reporters have questioned the cable news host’s cozy relationship with the GOP front-runner.

“The Republican front-runner’s failure to provide what should have been a simple answer has raised even more disturbing questions about the man who is on course to lock down the GOP’s nomination for president,” the host of MSNBC’s “Morning Joe” wrote in a Washington Post op-ed.