Trump was evasive on healthcare, evasive on his tax returns, was evasive about his losing to Clinton in the polls, kept repeating himself while denying that he repeats himself and while criticizing Rubio for repeating himself too much, etc. I agree with Leon Wolf:
Here’s what a bad night it was for Trump. In the middle of a completely innocuous question from moderator Hugh Hewitt, which was not in any way attacking Trump, Trump out of nowhere slammed Hewitt with “No one listens to your show.” In the span of 20 seconds, he said “I don’t believe anything Telemundo says,” and “I love Telemundo. Everything is fine.” Literally within the same answer. The belief this entire time has been that Donald Trump cannot be rattled in a debate. Tonight proved that it is not true. It’s one thing to expose Trump as a liberal; what the other Republican candidates did tonight was to expose Trump as a lightweight. Trump has gotten away for months with not having answers to anything because no one has pressed him on the point. Tonight, that ended, and he looked like a child.
Trump's unprovoked insult of Hewitt reflects Trump's character. Imagine if any other candidate had done that or had done even half of the rest of what Trump did in this debate. Rubio's relatively minor mistakes a couple of debates ago got a major amount of media attention and had Rubio getting criticized widely for days on end. Will Trump get the far worse treatment he deserves, now that he's so obviously had a debate performance vastly worse than what Rubio had in that previous debate? I doubt it. We'll see how many voters are discerning enough to realize what happened in tonight's debate. Trump got knocked out by Rubio, was propped up and knocked out again by Cruz, and kept getting the same treatment over and over the rest of the night. He was a punching bag getting hammered back and forth between Rubio and Cruz. Will the media cover the debate that way? Will voters respond to the debate as they ought to? Rubio and Cruz did their part. If the media and voters don't respond as they should, then the media and the voters are to blame.
Oh, and Kasich and Carson were there, too. I think.