My personal impression is that Rubio turned in one of his weaker debate performances in the series, although admittedly he was on the defensive taking shots from Cruz and Rand Paul in particular.
Carson didn't particularly impress me; he needed a strong performance to shore up support as he is trying to battle Rubio for third--and I don't think he got it.
My guess is if the debate does effect the polls, Cruz gains over the other candidates, drawing into a single-digit gap behind Trump. It's probably more of a stealth gain on others, points at a time. I don't think Rubio is in a bad situation; he has competitive poll numbers against Clinton, and I think Trump and Cruz are looking at roughly the same segment of the GOP base. It's very possible Rubio picks up support as other candidates drop from the race and becomes the candidate of choice for those who think Trump and Cruz are both unelectable. But that hasn't happened yet.
Of the other candidates, Rand Paul, Jeb Bush, and Chris Christie impressed, probably at Rubio's expense. Fiorina and Kasich needed a good night to shore up their campaigns and didn't get it. Bush turned in a long-overdue more aggressive performance, notably rebuking Trump as the "chaos candidate"; the problem is that it may have been too little, too late.
The debate was on defense policy, terrorism, refugees and the like. I think this type of debate generally favors current or past federal legislators or those with State/Defense Department/White House experience. They generally have more fluency in salient issues, strategy, intelligence matters, hardware and personnel, etc. That would tend to favor the 3 senators and Gov. Kasich, who had served several terms in Congress. Their strategy in dealing with those without comparable exposure would be to argue those others are too inexperienced to serve as Commander-in-Chief.
If you are in the non-DC pool, there are some strategies, e.g., argue the necessary role of an independent civilian Commander-in-Chief (Carson); demonstrate one's literacy of modern military hardware and constraints, strategic challenges (Fiorina); establish one's proven public sector leadership during state crises (e.g., Christie talking about his performance during Hurricane Sandy and its aftermath and his role as a US attorney post-9/11); discuss the division of labor and executive ability/experience in recruiting the right leadership for the Pentagon (Trump); suggest that the federal insiders are part of the problem and have contributed to the current deficient state of affairs (Trump). One should not argue, like Palin did, that one as a governor has experience in relation to his or her command of the state National Guard or the presence of military bases in the state.
There are still some obvious issues here: for example, Bush notably mishandled post-invasion Iraq, and he, having deferred to the military leadership, failed to pull the trigger on a deteriorating strategy until after the disastrous 2006 mid-term election. One certainly can question Bush's judgment to depose Saddam Hussein, opening the Pandora's box of sectarian conflict, something his own father avoided at the end of the first Gulf War; the evidence Iraq posed an existential threat to the US was, at best, dubious and speculative. Oddly enough, it was Jeb Bush himself who rebuked Trump on his theme, arguing that Trump couldn't consult his way through the Presidency.
I was actually mildly surprised that the rest of the field, all of them neo-cons with a hard line on the battle against terrorism, didn't go after Rand Paul as a piñata, with the usual isolationist nonsense as they did earlier in the campaign. Perhaps they didn't feel that there was much political gain to be made because Paul barely qualified for the debate on poll results.
I thought that Rand Paul had an excellent night, particularly in shoring up his dispirited libertarian base. It was quite clear everyone else considered the Defense budget sacrosanct and in fact had badly deteriorated during the current administration; they all were ready to spend big money, including Trump, to ensure that our big ticket items, like obsolete, shrinking pools of planes and ships, were amply replenished with the latest, greatest technology. Paul resurrected his talking point about the biggest threat to our national defense being an increasingly out of control national debt. There was no real response to Paul's challenge; in fact, there were gripes that the sequester, which called for mutual restraint on the DoD and domestic discretionary spending, had damaged Defense. Paul was particularly critical of Trump (who seems open to regulating the Internet, which he considers to be a key resource for the jihadists) and Rubio (over his willingness to compromise privacy in giving the NSA all the resources it wants in the fight against terrorism and his role in the failed immigration bill during an earlier session of Congress, which Paul ludicrously described as open borders). I do think Paul also made an unappreciated challenge to the Bush doctrine (not in so many words) of using military force to promote our democratic ideals. Paul also notably rebuked Christie's position in favor of stepping up our activities in Syria (e.g., no-fly zones) as potentially destabilizing and risking a start to WWIII.
On the other hand, I notably disagree with Rand Paul's populist positions against immigration and refugee admission, which I find are inconsistent with a pro-liberty perspective.
My rank order of debate performance in descending sequence:
- Rand Paul
- Ted Cruz
- Jeb Bush
- Chris Christie
- Marco Rubio
- John Kasich
- Ben Carson
- Carly Fiorina
- Donald Trump
