Trump doesn't have any diplomatic skills whatsoever. He would get us killed.
His purpose this go-round would be akin to Sarah Palin. People would like a few of his no-nonsense views for about five seconds, in a hypothetical world. His presence would require a few of the "serious contenders" to perform differently. You could stand any asshole behind that Trump podium, and they'd have to address that asshole, as well.
My dream darkhorse is David Letterman. Now he would be a pleasure to watch, in place of Trump, and ultimately everybody would know it's a ruse. But people just don't understand Trump is a.. I donno even what to call him. He's a thing. He's a joke. He's like the political version of a funhouse mirror. He would never even be there if people didn't want to look at a warped illusion.
But putting "the football" in Trump's hands, fo' real. No way. Its not even remotely funny.