“U.S. Grant’s Attorney General was impeached after resigning, so the precedent is there.”
It is true that they have proceeded against officials that have already resigned, but the issue has never gone before a court because the action caused no injury for which to bring a case (the guy’s already out of office)
Congress can put on a performance but that doesn’t mean that it has any legal consequence
An interesting take on this: since the “precedents” were all for officials who resigned in order, (apparently), to avoid impeachment the precedent would not apply to PDJT since his impeachment trial is after his constitutional term of office has expired.
In other words, he did not resign to avoid impeachment. He remained in office during which time impeachment could have been voted on, (was in 2019), sent to the Senate and then a trial held. The timing of the trial, (if there was a political desire to have one), was/is totally up to the Senate to determine. It is like a DA holding onto a case, without indicting, until the statute of limitations passes and an indictment can no longer be issued.