I dont know what you arent understanding. If he is the nominee, and trump is his opponent, you should vote for gavin. If you are "never gavin" that means you would not vote for him even against a trump 3rd term. Same as people not voting for harris against trump in a second term
Or, as I said, the Democrats could pick a non-pos candidate now that they’ve been warned that picking Newsom means they lose. Why are you blaming the people who won’t vote for him and not the Democrats for picking him, knowing enough of their core vote won’t vote for him to mean they lose?
2/ Especially as both options are theoretical and neither’s happened.