Jeb takes a swipe at Trump and Trump hammers him:  He doesn t really believe I m unhinged. He said that because he has failed in this campaign. It s been a total disaster. Nobody cares. And frankly, I m the most solid person up here. I ve built a tremendous company and all I want to do is make America great again.  .@realdonaldtrump:  With Jeb s attitude, we will never be great again  https://t.co/2cXmVJqD3m #GOPDebate https://t.co/tHxzrB3PIe  CNN (@CNN) December 16, 2015Round Three: 