Trump has systematically insulted every demographic in America and shown through his ever changing comments on his own freaking policies that he just goes up there, spouts whatever he feels is gonna make people happiest at that time, and leaves. Doesn't matter what you run him against at this point...the other candidate would be a better choice regardless of who it is.
Even if you are a Republican, this guy doesn't stand for anything but branding your party with so many stains that it'll never come clean enough in its image to win again. He doesn't know policy, he advocates war crimes, he's a misogynist, a racist, a complete xenophobe who thinks he can isolate us from all the world and piss all over them in the process and somehow NOT cause wars or cripple us on the world economic markets causing us to fall further behind, he's not paid taxes in nearly 20 years, someone who dealt illegally in trade with Cuba and Russia who is more than likely still backed by Russia given that US banks blacklisted him and a majority of his business was shimmed up by them, someone who misuses charities for tax shelters and self funding, is a habitual liar and not even good at hiding it given all the recordings we've seen, a draft dodger who openly mocks PTSD victims and real war heroes and someone who actually has the gall to think they are a hero for getting out of everything.
He'd burn the whole country but so long as he made it out of the fire okay at the end he'd brag about how smart he was and how he was fine making him better than everyone else who got destroyed during his reign.