“He is extremely emotional and volatile and responds to any perceived slight. He knows almost nothing about policy and, like a lot of lazy people, tries to assert he doesn’t need to know. He has little or no support staff that can help compensate for his weaknesses. And most importantly, Trump thinks he is going to win. That’s a huge potential asset to an opponent if Trump starts to feel that his ‘victory’ is in jeopardy.”
Also: Trump has been operating at an advantage in that his opposition is entirely putzes.
Any Republican candidate in the last 35 years could take Trump’s lunch money and make him cry: Reagan, Bush Sr., Dole, Bush Jr. with Rove (but not without), or Romney.
Trump has the advantage of running against a team that’s even bigger losers than he is. Which is saying something.