Michael W. McConnell and Ken Gormley argue in the Washington Post that “the constitutionality of a Senate trial on Trump’s impeachment is not seriously in doubt.” They think that the House may not impeach an official who has left office but that the Senate may try a former official who was impeached while still in office.
A lot of the arguments I’ve read for late impeachments and trials are based on the function that the impeachment process was evidently meant to serve, one aspect of which is to disqualify an official from holding office again if the Senate so votes. On that logic, one would have to conclude that both late impeachments and late trials are permissible, since otherwise officials facing imminent impeachment could always avoid disqualification by resigning before they were impeached. I find this line of reasoning persuasive, as I’ve noted elsewhere, but its plausibility does seem to diminish the longer an official has been out of office. If the House, let’s say, waits three years to impeach a former official, with control of the chamber switching parties in the meantime, the impeachment will look more like a new political vicissitude, perhaps vengeful or self-interested, and less like a response to clear wrongdoing.
What’s noteworthy about the M&G argument is that it’s purely textual, rooting the constitutionality of a late trial for Trump in the Senate’s power to try “all” impeachments. The whole op-ed is worth a read, but here’s an excerpt:
Trump’s impeachment by the House of Representatives, seven days before he left office, was unquestionably valid. The only question is whether, now that he is back in private life, he may be tried by the Senate. The Constitution provides a clear answer, giving the Senate “sole Power to try all Impeachments.” The key word is “all.” The Senate’s authority explicitly extends to every constitutionally proper impeachment.
Concerns that trying Trump would set a dangerous precedent for launching impeachments of past officers, even going back many years, confuse impeachment with the trial of an impeachment. The Constitution gives the House authority to impeach the “President, Vice President, and all civil Officers of the United States.” It doesn’t expressly say they are the only persons subject to impeachment, but the best reading, under established principles of legal interpretation, is that the list is exclusive, and that the House therefore cannot initiate impeachment proceedings against former officers.