in general. He has ran an incredible smart campaign so far. Basically using GOP and media to support of his 3rd party run. I still believe he wasn't serious at first, but once the ball starts to roll, he realize exactly what he need to say to keep it going. But I think he is also smart enough to realize this wouldn't carry him through General, so if he really wants the presidency, I believe he'll start changing his stance in many things. I could also see him hand the presidency to Clinton as he can just blame the GOP establishment for the loss and make a lot more money, less stress, and still be a high profile public figure.

Will he be an embarrassment for American presidency? Very possible, but I do think if Trump do win the presidency, it could really shake up the political land scape, which in long run, might be a good thing. I'm not too concerned about his unpredictability. My guess is congress will essentially block everything.