“To “impeach” is to make an accusation. “
They can only impeach the President, and anyone not the President is not impeachable. I am surprised I have to say this, but, Trump is no longer the president after he leaves office and the House cannot impeach private citizens.
First of all, the fact that the President, Vice President, and all civil officers can be removed from office by impeachment certainly means that MANY serving officials can be impeached by the House (not just the President). At least 8 Federal judges have been impeached and removed, most recently Alcee Hastings, a judge in Florida who is now serving in Congress (Members of Congress cannot be impeached).
Second of all, although removal from office as a punishment is reserved to the President, Vice President and all civil officers, disqualification from holding office in the future is NOT restricted in this way.