You do know, that the Constitution can be amended...right?
It takes a bit of work...and it's not as easy as bumping Henry Wallace off of the ticket, at the Party convention... But it can be done ... Whether by concurrence by a certain number of the States, and a successful vote in Congress...or even by a special Convention. And one of the ways the Constitution has been subverted, is by ignoring all of the States that have pushed for one...
And I'm not on the right, and not a Trump supporter - before you start going in that direction...