From NBC's Mark Murray
McCain's coup de grace over Romney:

"You are certainly the candidate of change."

From NBC/NJ's Mike Memoli
In case you missed the new polls, this immigration debate shows you who is at the top in New Hampshire.

Romney and McCain's heated battle really doesn't seem to be so much about the policy anymore, but instead about the person. McCain indirectly called Romney a "liar" for calling his plan amnesty.

And, as I was discussing with a smart colleague earlier tonight, Romney will have a hard time undermining McCain's credibility here in New Hampshire. McCain's net favorable rating, according to the newest UNH/WMUR/CNN poll, is 68%. Romney's is only 37%.

And by the way, Giuliani may score points by offering perspective -- even Ronald Reagan offered so-called "amnesty," and no one's record is perfect.

From NBC's Chuck Todd
"You are the candidate of change" -- McCain to Romney... the soundbite of the night; Romney may end up coming out firing big time tomorrow; he's got to be frustrated by the multiple cheap shots.

From NBC's Andy Merten
Which issue do you wish the Republican candidates spent more time on?
1.  Economy 30%
2.  Immigration  11%
3.  Environment  28%
3.  Healthcare  20%
4.  Iraq War  10%

This poll is still going on, and obviously billed as a post-debate question, but it's still indicative of the emphasis placed on domestic issues by young people.

From NBC's Mark Murray
The difference between Huckabee's answers on illegal immigration tonight -- calling for tough border enforcement -- and back at the CNN YouTube debate in late November -- when he, compassionately, defended awarding college scholarships to the kids of illegal immigration -- is pretty striking.

The answers aren't necessarily inconsisent, but the tone definitely changed.

From NBC/NJ's Matthew E. Berger
Giuliani has always talked about Ronald Reagan on the campaign trail a bit, but he has mentioned him numerous times tonight. He is definitely trying to draw a parallel with the Republican icon in ways that he has only hinted at before.

From NBC's Domenico Montanaro
Huckabee was given a gift, going after everyone else was bickering about the details. He again tried to be the unifier, got to be the voice of reason without having to defend his positions. He spoke to emotions and border security first.

From NBC's Domenico Montanaro
Rudy set up Romney on his Reagan comment. He lured Romney in, and then hit him with saying that he thinks Romney would have attacked Reagan in his ads for granting amnesty. "The hero of our party," Rudy proclaimed, arms raised in the air.

This debate is showing pretty clearly the differences "in the weeds" as they say about where the candidates stand on immigration. By my count, it's Rudy and McCain v. Romney and Thompson. To you, Gov. Huckabee... He's been quiet.

From NBC's Chuck Todd
Wow, the entire field really is ganging up on Romney. Arguably, I think Thompson's position on immigration is closer to Romney's position than McCain's and yet, Thompson hit Romney just now...

From NBC's Chuck Todd
Why didn't Giuliani make a bigger stand in New Hampshire? Doesn't he ideologically fit New Hampshire even better than McCain?

From NBC's Chuck Todd
Unlike Iowa, New Hampshire isn't a hotbed for the immigration debate and McCain should be able to navigate this issue well here. Now, Michigan? South Carolina? That could be a different story.

From NBC's Chuck Todd
McCain just put himself on the populist side of the Rx drug fight by attacking the pharmaceutical companies while Romney defended them. This is a core disagreement among some in the Republican Party, main street vs. Wall Street.

From NBC's Domenico Montanaro
McCain called the pharmaceutical industry the bad guys, but Romney was quick to come to their defense, saying they create the medicines that keep us well in the free market. It was an interesting exchange and an interesting divide that hasn't really been exposed before.

*** UPDATE *** NBC/NJ's Adam Aigner-Treworgy adds, In Romney's last answer before the commercial – "Don't turn the pharmaceutical companies into the big bad guys," – he might have played right into Huckabee's new NH strategy. After a victory in Iowa, Huckabee is trying to rid himself of the concept that he can only win in states with high evangelical populations by positioning himself as the populist Republican candidate. Every time he sticks up for big business, does Mitt Romney look like the big business candidate who can't relate to the average voter?

From NBC's Mark Murray
I think even the most ardent Romney supporters would agree that he didn't handle the question on his MA health-care plan all that well.

There was a bit of a deer-in-the-headlights look when Thompson challenged him on the plan.

From NBC/NJ's Adam Aigner-Treworgy
"Our policies often reflect what's going on at the time."

This is an issue that hasn't come up too much on the trail. It seems reporters have been trying so hard to make sure that Huckabee keeps up with the news of the day that they haven't been able to quiz him on his stance on consistency or on policies of the past. Does this line make him sound a little soft on flip-flopping?

From NBC's Chuck Todd
If this is the format for the Democrats, it's got "race is frozen in place" all over it. The guy with the momentum, Obama, must be very happy with this.   It's possible the Republicans believe it's easier to go after each other on cable than on broadcast. It could very well be the subdued nature of this debate is all about the fact that this will be the largest debate audience these candidates have had to date. So should we expect the real Republican fireworks tomorrow on Fox News where red-meat eating Republicans will be watching?

From NBC's Andy Merten
It looks like Facebook is continuously putting out polls during this debate.  This is, again, a poll of young people who use Facebook -- not a reflection of New Hampshire primary voters or the electorate in general.  But here's another poll on the segment on foreign policy:

Do you feel more informed about the Republican candidates' position on foreign policy after this last exchange?
1.  Did not see the exchange:  5% (63 voters)
2.  No:  33%  (433 voters)
3.  Yes  62%  (800)

Again, this poll is only indicative of young people watching.  Then again, more college students may be tuning in while still at home on winter break.

From NBC's Andy Merten
Facebook, a co-sponsor of this debate, is polling its users -- mostly college students and 20-somethings -- of their impression of the candidates in the debate so far. The questions and results so far:

1. Is tonight's debate giving you a better sense of whom you will vote for?
Yes:  67% (581 voters)
No:  33% (288 voters)

2.  Is a Presidential candidate's national "electability" a big factor in deciding your vote in the primaries?
Yes:  37% (6,747 voters)
No:  63% (11,367 voters)

From NBC/NJ's Adam Aigner-Treworgy
"I'm not running for George Bush's third term," Huckabee said during his second shot at the foreign policy question. After staying out of the foreign policy back and forth between Thompson, Romney, Giuliani and Ron Paul, Huckabee chimed in with a nice line of defense. He went after Romney for comments on 60 Minutes and for not reading his controversial article in Foreign Policy, and when asked by Romney to let him talk about his own policy Huckabee hit back with "which one." If being nice paid off in Iowa, Huckabee seems to feel that going right after Romney might help him in New Hampshire.

Any reporter covering the Huckabee campaign knows that there is no love lost between the two governors in the GOP primary race. But ABC's decision to place them right next to each other and kick off the debate with the topic that has caused the most heat between them on the campaign trail certainly made the first half hour a vibrant exchange.

From NBC/NJ's Matthew E. Berger
Giuliani definitely benefits from terrorism being the first topic of conversation. He gets to show his knowledge of the subject, and makes a 9/11 reference or two.
 
"I could go on and on," Giuliani said as part of the team effort to refute Ron Paul.

From NBC/NJ's Mike Memoli
This back and forth on Iraq was getting just about everyone dizzy. But Mike Huckabee got the first major "whoa!" from the press filing center with his not-so-subtle dig on Mitt Romney's positions.
 
"Don't characterize my position," Romney said.
 
"Which one?" Huckabee responded. As Romney reacted, Huckabee looked very pleased with himself.

From NBC's Chuck Todd
What an advantage for McCain to be able to answer the principle question first. BTW, Romney answered the question as well as he could have, leading with his strongest foundation -- his impressive family

From NBC's Andy Merten
Huckabee defended his support of Bush's foreign policy by saying he supported the initial invasion of Iraq in 2003.  Romney's rebuttal was that he supported the troop surge of January 2007 -- not the initial invasion.

From NBC's Chuck Todd
"I am not running for George Bush's third term." That's a Huckabee quote that could play well with indies in New Hampshire; it's one we may hear a lot now that Huckabee needs to find more supporters beyond his conservative flock.

From NBC's Chuck Todd
This kicking around of Ron Paul by the field doesn't make many of these candidates look too presidential. It's become an easy trick at these debates since, frankly, Ron Paul doesn't speak for a large majority of Republican primary voters. It's a waste of these guys' time now.