The Republican debate last night in South Carolina left me with a few impressions and the strongest two of them were not about the candidates directly. That said, here's a quick summary of my immediate thoughts.
(1) The crowd was far too involved. Disproportionately involved is probably a better way to put it. The crowd seemed to be firmly behind Bush first, then Kasich and then maybe Rubio. That does not reflect polling in the state and often did not reflect what was being said by the candidates. At times it seemed like they were booing for the sake of booing a specific candidate. Trump claimed they were all Bush donors. What's more likely is that each candidate tried to stack the hall with supporters/volunteers provided with instructions on how to respond.
(2) The moderator John Dickerson was both prepared and unprepared. As a moderator Dickerson asked measured, intelligent questions. He deserves credit for that. Secondly as to the audience stepping on candidates' responses he did not seem prepared for it and made no obvious effort to control it. Similarly he allowed the back and forth between candidates to go on too long in many cases. I applaud him for not stepping on candidates' talking and allowing more back and forth. However, he did not manage the perfect balance between allowing the back and forth, and keeping the debate from bogging down in tit-for-tat talking. All that said, on balance he did a good job overall, especially when compared to many previous GOP debate moderators in the past 8 years.
(3) Donald Trump seemed to take a lot of the jabs from Jeb too personally. It came across as bitter. He started strong on the SCOTUS issue suggesting openly that the GOP controlled senate should delay on any Obama nomination. Then he got into it with Jeb and made the debate about the two of them. It's been called swinging down and it helps Jeb and hurts Trump. Trump should stop it if he wants to win. Trump did manage to even himself out later in the debate and finished strongly.
(4) It was Jeb's strongest performance yet in terms of actual debating. He did the right thing by attacking Trump because it kept him in the limelight more than his ranking merits. It did nothing to change his image as an establishment RINO.
(5) Kasich's message of not attacking fellow Republicans was a good one but... Two problems: (i) It's not practical right now for the candidates to do that. The need to show they can mix it up for when they face Clinton or Sanders, and more urgently, they need to gain or protect their existing support levels among primary voters. (ii) It would carry more weight if he had not started the debates by slagging Donald Trump really hard. It's a bit hypocritical or at least a flip flop.
(6) Rubio did much better than his New Hampshire debate. He probably did not do as well as he needed to make up most of the ground he lost as a result of the Chris Christie tussle last time around.
(7) I did not get a strong enough sense on the positions of most of the candidates on the Supreme Court. Perhaps that was too much to expect at that debate, but a strong answer from a candidate could have been a boon. None of the answers on the death of Justice Scalia were particularly bad, but they were certainly not enough to make an impression.