Not so much his policies (there aren’t a lot of them, honestly, since he’s not truly interested in governing), but his lack of them
And: his entire combative and hyperpartisan demeanor, his unpresidential Twitter wars that go nowhere, his steady assault on the ideas of impartial justice and truth, and the GOP’s willingness to destroy — for his sole benefit — the impeachment process as a real tool of holding presidents accountable for all practical purposes.
Trump didn’t testify (if he had, he would have perjured himself in a heartbeat). He did not even attend. He watched and tweeted from home.
The GOP wouldn’t call any new witnesses, not even Bolton.
Therefore, anything we know about what really happened in Ukraine is a result of efforts by House Democrats and House Democrats alone.
But one day we will find out more: the truth always has a way of coming out. Easiest way? Next Democratic President releases the blocked docs under subpoena.