you have nothing to worry about. Hillary wins in a landslide no matter who the repubs choose. The divisions right now in the repub party are a thousand times deeper than anything in the dem party. No matter who the repubs choose, a large chunk of repub voters are not going to show up again just like they did not for Romney or McCain. Either the tea partiers are going to stay home or the establishment is going to stay home depending on who they pick. There is no consensus candidate on that side. The dems can have a flat turnout and still win in a landslide.
Of course I agree with you that its important to not take anything for granted and all should turn out on both sides. But I don't think it will matter either way this time.
The proud man counts his newspaper clippings, the humble man his blessings.” Bishop Fulton J. Sheen