It would be such a relief if the USA split.
Who would care that there was a Trump presidency, if he was president of Florida Bananistan?
People in the northeastern nation, or the western nation could just get on with life, building their liberal democracies and making friends with Canada. The folks of the Great Plains nation, Lone Star and Jesusland could do their things as well.
It's trying to fit people with differences into a single whole that doesn't work. There really is no unity in America.