Not going to happen, but I wonder how a mixed party ticket would do. Kamala (or whoever) + Mitt Romney as VP ? Has it ever been done? Would it work to attract the center/swing vote, or more likely to be a negative?
No. The staunch Republicans will still vote for Trump and the only way to beat that is for there to be an incredibly cohesive force among a population that isn't very cohesive in the first place. The Republicans actually have it easy, they align and bond on lots of things. The center and left align on very few things and fight amongst themselves. A mixed ticket isn't going to align them better.
I have seen some videos of Trump voters who are claiming that JD Vance is a traitor to the white race for marrying a non-white. And their kids have non-white names.
They are quite upset about this. Some of them are so disgusted by this that they might not vote at all. One can only hope.