Trump is a successful marketer.
in terms of business, he's won some, and lost some, and about broke even with the market over the past 40 years. He could have invested the $ and never touched it, and he'd be worth 8 billion today. He worked for 40 years, and is worth between 3 billion (forbes) and 10 billion (his own claims).
He's a good businessman, but I'd say Romney was FAR more effective than Trump. Let's be honest... 4 high profile bankruptcies aren't good. And romney had good experience running a state as governor - trump is not a workhorse like that, nope.
Trump is out of control emotionally. THAT should be the point we're drilling home. Dude is unstable and truly cannot control impulses when anger hits him. 11pm tweeting or calling into CNN to mock reporters... that is what a person does when they can't control emotions.