George Conway, husband of White House counselor Kellyanne Conway, has a strong opinion about Donald Trump’s legacy. He’ll be remembered “without a doubt” as the “dumbest and worst” president, Conway declared in a tweet Friday.

Conway was responding to a tweet by conservative Washington Post columnist Jennifer Rubin commenting on Trump’s controversial July phone call with Ukraine’s president. The call — in which Trump repeatedly urged the Ukrainian leader to investigate his political rival Joe Biden and Biden’s son — has triggered an impeachment inquiry. Rubin called Trump “so thickheaded” that he “didn’t even realize what was incriminating” and “so foolish” that he took advice from his “unhinged” attorney Rudy Giuliani.