If we split at this point, all of the establishment Republicans would join the democrats. Really, what is the difference between them and Jim Jeffords or Lincoln Chafee? Nothing, those guys just were forced to switch. If the split ever came, the conservative party would become one of the two major parties, and the Republicans would fade into obscurity. It might take a few election cycles first, so if we could get the Presidency first, and then start taking over Senate and House seats after that, it would keep the damage to a minimum.
They’ve already joined the Democrats, years ago even. You’re looking at one-party rule.