Although the very definition of impeachment focuses on past acts while in office, the twin Trump impeachments have been about looking forward to the next election. The aim has been to knock him off the ballot if possible, but if not, dirty him up so he could be defeated.
The talk about Ukraine in the first trial and about the Jan. 6 Capitol riot now is a pretext. The real driver has always been the fear of what Trump will do, not what he has done. Neutralizing him as a political force and dividing the Republican Party are the ultimate aims.
Once you see that pattern, everything else makes sense. The flimsy evidence about withholding aid to Ukraine, based largely on a single phone call where Trump released the transcript, never had a chance of success in the Senate, and the impeachers knew it. Their aim was to beat him in 2020 and they did, though it’s unlikely that impeachment made much of a difference.
Having beaten him once, you might think the Dems would no longer be afraid of Trump. But they are, which is why they are desperate to keep him off the 2024 ballot. They probably won’t succeed but their endless effort to find a mechanism reveals their fear.