I am unaware of anyone who formerly was a Trump detractor, yet who has become a Trump supporter since the impeachment hearings began.

Of course, the same may be said, in reverse.

This suggests that many (on both sides, actually) have preconceived beliefs, that are simply impervious to any evidence--one way or the other.

There is a name for this sort of reasoning: It is the a priori fallacy.

But perhaps someone can point me to a person who has changed his (or her) mind--on either side-- since the hearings began.