I think once the field whitles down to 3 or 4, he is going to get crushed the moment he gets good poll numbers or has a good week. Donors who have money on other candidates will say "bring Ukraine up, we can't risk him improving". It's his kryptonite and will be called out when necessary if anyone hopes of having a shot at winning.
It's ironic. If the Dems had not pushed for this impeachment and the transcript not released, Trump would have been relegated to raising the issue during the 1 on 1 debates with Biden. The Dems could easily have called it out as "conspiracy" and brushed it off as Trump losing on issues. With so much going on in the focus of the election, it would have been far more effective.
Now, THEY are the ones who are effectively saying "we can't beat you on issues, so we try to impeach you on trying to ensure corruption of Biden is confronted. How dare you do that for political reasons!".
They in effect, tossed his campaign under the bus. By design by one of the socialists, I imagine. It's become so worrisome that Bidens team has reached out to media network to demand they not invite Rudy on to spread conspiracy theories and the like.
What a horrible look. The Dems did it to themselves and Pelosi knows it now. She was outplayed by the alt-left.