But J. Michael Luttig, a former judge on the United States Court of Appeals for the Fourth Circuit, makes a convincing case that no, it is not constitutional to impeach a former president. He first laid it out in a few tweets on Monday morning and then elaborated in a phone conversation Monday evening.

“The crux of my argument is that the very purpose of the impeachment power is to remove an incumbent official,” Luttig said. “That seems to me to be crystal clear and inescapably true under the text of the Constitution itself.”…

The plain meaning of these passages is that impeachment, in the case of a president, is designed to remove that president from office. A secondary purpose is to disqualify a removed president from ever holding federal office again. “It’s the impeachment that is the authority for the disqualification,” Luttig said. And a former president, by definition, cannot be removed from office. And, by the way, the Constitution specifically lays out the way to deal with wrongdoing once the president is out of office: He will be “liable and subject to indictment, trial, judgment and punishment, according to law.”