If Trump was being sarcastic, doesn't that mean he thinks Obama has been America's hero?

If sarcasm is used to indicate the opposite of what is being said, then Trump must mean that Obama is the number one enemy of ISIS? http://www.nydailynews.com/news/politics/giuliani-defends-trump-apparent-call-clinton-assassination-article-1.2745490
“If Donald Trump was going to say something like that, he’d say something like that.”
Did he mean that Trump would have said Go and assasinate Hilary Clinton?” And that he can imagine him inciting vilolence?: http://www.businessinsider.com/donald-trump-legal-fees-punch-protester-2016-3
“If you see somebody getting ready to throw a tomato, knock the crap out of them,” Trump said. “Just knock the hell — I promise you, I’ll pay the legal fees.”