Rose threw down the gauntlet shortly before 6:30 p.m. Wednesday when he hopped on his seldom-used Twitter account and declared to his 1.2 million followers, without context, “Whatever anyone may have previously thought of Steve Mnuchin he’s officially an a–hole.”

“It’s official!” tweeted the rock star, who is a prominent critic of President Trump.

Then, in a move that prompted collective surprise, Mnuchin hit back.

“What have you done for the country lately?” he tweeted, tacking what appeared to be an emoticon of the United States flag to the end of his response.