Trump can still be impeached as an ex-president.
History gives little guide on the question of whether a president can be impeached once he leaves office, and House lawyers were racing to understand the legal and constitutional issues.
There is precedent for doing so in the case of other high government officers. In 1876, the House impeached President Ulysses S. Grant’s war secretary for graft, even after he resigned from his post. The Senate at the time considered whether it still had jurisdiction to hear the case of a former official, and determined that it did. Ultimately, the secretary was acquitted.
Michael J. Gerhardt, a constitutional scholar at the University of North Carolina who testified in the last impeachment proceedings, wrote on Friday that he saw no reason Congress could not proceed.
“It would make no sense for former officials, or ones who step down just in time, to escape that remedial mechanism,” he wrote. “It should accordingly go without saying that
if an impeachment begins when an individual is in office, the process may surely continue after they resign or otherwise depart.”