Sorry if this has been asked before. What would happen if TFG drops out of the election?

[Jirel]

34. Not that it's going to happen, but...

It’s super straightforward. Who they’d have step into the election, assuming it happens before the deadline to change ballots in the various states (Texas’ withdrawal deadline is 74 days prior to Election Day, for example), is anyone’s guess. But a party can choose whoever it wants to run. The GQP could call an emergency convention (by phone, if needed) and nominate someone else.

It’s not entirely uncharted water. We have had candidates die between nomination and election. Here’s an article on what has happened in congressional races. Death or withdrawal late would basically work the same.
https://www.washingtonpost.com/news/the-fix/wp/2014/10/01/five-people-have-won-election-to-congress-despite-being-dead/

In Dump’s case, if he withdrew too late (it would be pointless to do so after various states’ withdrawal deadlines, and that’s coming up fast) or died, idiots would still be able to vote for him and Corporal Press Release. If the ticket won, Vance would wind up being inaugurated instead.