538 has current polling vs 2020 at the same time and at least for PA and MI Trump is way higher now vs 2020. I think I looked at national as well and that was also in Trumps favor vs 2020.
Do you want me to start elaborating all the prominent Republicans who have left that party, or are voting for Harris, this time?
Yes, there's examples the other way, too, but don't fool yourself that they in any way comparable.
Or do fool yourself if you insist. Your choice!