I’m not doubting you. I don’t know the rules. Do you have a link to the rules you could post?
“I don’t know the rules. Do you have a link to the rules you could post?”
No, I don’t have a link handy, but I do know that the parties are allowed to choose their nominees in any way they see fit.
Currently, both major parties conduct a primary election to determine who that person will be. You’d probably have to look up the specific rules regarding how a Democrat nominee is replaced. Try the DNC website.
Awarding the spot to anyone but the runner up in the primary election would be a huge break with American political tradition, but who knows? Perhaps the choice would be made by a hastily reconvened gathering of their delegates and superdelegates.