By MICHAEL FALCONE ( @michaelpfalcone ) and AMY WALTER ( @amyewalter )

CHARLESTON, S.C. - With one more obstacle out of his way, Mitt Romney appears to be another step closer to securing the Republican nomination.

In a state like South Carolina where the Republican electorate includes a large share of social conservatives and evangelicals, Jon Huntsman's decision to exit the race and endorse Romney may not give him a huge bounce, but it could be just the edge he needs six days from today when Palmetto State voters cast their ballots.

As ABC's Jonathan Karl points out, Huntsman's departure is significant because most of his votes come from Romney. In South Carolina, even a margin of just four or five percent could be the difference between first and second place. Now the more moderate wing of the party is united while the social conservatives remain divided.

Huntsman's campaign was also the most effective - by far - at exposing Romney's record of flip-flopping. Team Huntsman produced a series of devastatingly funny videos and websites at Romney's expense . (Most of them have now been purged from the Internet.)

In recent interviews, he said to our Jon Karl that Romney was "completely out of touch," and told ABC's John Berman that Romney was unelectable and "has not put forth reason to give us a reason for us to trust him."

It's clear that there is no love lost between the two Republicans.

For their part, the Romney campaign is not exactly greeting Huntsman's exit with open arms. Romney will not be by Huntsman side later today when the former Utah governor formally bows out and throws his support behind his one-time rival.

One reason why: Romney does not necessarily benefit from Huntsman's endorsement as much as he benefits from Huntsman simply no longer being in the race. Gaining the support of a moderate is not exactly the message the Romney campaign wants going into the final days of the South Carolina primary. Remember, Newt Gingrich has been spending a lot of time and money in the state bashing Romney as a "Massachusetts moderate."

Though the Huntsman news is likely to dominate the day, by tonight all eyes will be on the debate stage in Myrtle Beach where the five remaining GOP hopefuls - Romney, Gingrich, Rick Santorum, Rick Perry and Ron Paul - will gather for the first of two face-offs before Saturday's primary.

The candidates largely whiffed in their debate outings ahead of the New Hampshire primary. This is now their last best chance to coalesce support among conservatives and force Romney into a serious fight in Florida. And no Huntsman on stage means one less person engaging in Mitt Bashing (or speaking Mandarin for that matter).

The biggest question is whether Santorum and Gingrich will bring their A-game to Myrtle Beach tonight.

WHY HUNTSMAN LEFT. Sources familiar with Huntsman's thinking told ABC News that after concentrating most of their time and resources on New Hampshire, the campaign was hoping for a second-place finish there. But Huntsman's third-place showing was not enough to keep money flowing into the campaign's war chest or boost their poll numbers in South Carolina. There was nowhere to go but away. A source close to the Huntsman campaign said the former ambassador to China and Utah governor was "proud of the race that he ran" but "did not want to stand in the way" of rival Mitt Romney, the current front-runner for the Republican nomination. "He has been discussing with his family after they woke up after a successful evening in New Hampshire," a Huntsman aide told ABC. "They felt good about their performance in New Hampshire, but he and his family had a discussion and this is the decision they came to," the aide said. "At the end of the day he decided he did not want to hurt the best chance of beating Barack Obama and that's Mitt Romney. By continuing into South Carolina and Florida, that's what he would have been doing." Word of Huntsman's decision comes the same day that the biggest newspaper in South Carolina endorsed him. The State newspaper of Columbia touted Huntsman's resume, pointing to his record as governor of Utah, and his service as ambassador to both Bush and Obama. In an interview with ABC News, South Carolina Republican Party Chairman Chad Connelly praised Huntsman for running a "spirited campaign" but acknowledged that his exit from the field "doesn't change the dynamics of the race" in the Palmetto State. http://abcn.ws/w1Sqbl

GINGRICH SPIN: "With Governor Huntsman dropping out, we are one step closer to a bold Reagan conservative winning the GOP nomination," said Gingrich's spokesman R.C. Hammond reacting to the news.

SANTORUM SPIN:  At a breakfast even in Columbia, S.C. today, Rick Santorum responded to Huntsman's decision: "Moderates are backing moderates,  that's the bottom line. It's no surprise. Gov. Huntsman ran as a moderate trying to compete with Gov Romney for the establishment moderate vote. Gov. Romney had a leg up on him as being a solid moderate that the establishment could get behind and Gov Huntsman wasn't able to crack through that. I'm not surprised at that at all and I anticipated."

More on Huntsman's decision from ABC's John Berman on "Good Morning America" today. WATCH: http://abcn.ws/wPym0D

PALMETTO STATE LANDSCAPE. ABC News' Rick Klein gives us his 30,000-foot view of the South Carolina primary heading into the closing week of campaigning: "Since the Palmetto State debuted its 'first in the South' Republican primary in 1980, the winner has gone on to the nomination every time. No non-incumbent Republican has ever won both Iowa and New Hampshire, much less the first three states to weigh in on the process. Polls suggest Romney is in a strong position to do just that. That's the backdrop for this weekend's move by a group of prominent social conservatives to throw their support behind Rick Santorum. One prominent attendee at the meeting promised 'activity' on behalf of Santorum in advance of Saturday's primary in South Carolina, but the quasi-endorsement doesn't seem likely to change the campaign's fundamentals. The move is both too late and too tepid to be likely to move the needle away from Romney. More importantly, the anti-Romney opposition forces remain too disparate to unite behind a single candidacy. Santorum, Perry, and Gingrich are all banking on South Carolina's evangelicals to boost them over the Mormon Romney. But there aren't enough of them to go around when split three ways; just ask Romney and the other would-be 2008 nominees who chopped up the vote and gave the state to Sen. John McCain four years ago. Add to that the fact that Romney actually received the votes of more self-described evangelicals in New Hampshire than any of his rivals, and the strength of Romney's position starts to come into focus. http://abcn.ws/yhRVcz

DEBATE DAY: Fox News' Bret Baier will co-moderate tonight's debate in Myrtle Beach along with Gerald Seib of the Wall Street Journal. The debate takes place at 9 p.m. ET at the Myrtle Beach Convention Center.

DEMOCRATIC COUNTER-PROGRAMMING.  Democrats plan what they are calling a "full-time presence" in the Palmetto State this week, starting today. Democratic Governors Association Chairman Martin O'Malley and Democratic National Committee Communications Director Brad Woodhouse will react to the GOP/FOX News Debate on Monday in Myrtle Beach with a 2:00 PM press conference at the Breakers, one on one interviews with national cable outlets and local and national newspapers before and after the debate.  DNC Chair Debbie Wasserman Schultz, DNC Vice Chair and Minneapolis Mayor RT Rybak and DNC Executive Director Patrick Gaspard will all be in the state later in the week to offer their perspective on the GOP race.

The DNC says it will be "using a new visual to tell the story of Mitt Romney as the incredible shrinking job creator." View it here: http://bit.ly/x9nvFZ

 

THE BUZZ

STEPHANOPOULOS ON COLBERT. One never knows when interviewing any newsmaker if they're being 100 percent truthful. But when interviewing comedian Stephen Colbert Sunday on "This Week" about exploring a possible bid for president, it was even more difficult to tell truth from fiction, ABC's George Stephanopoulos writes. But what does it matter when the fiction is so much fun? Colbert says he is not yet launching a campaign, but instead forming an exploratory committee- albeit a committee that will include "a brain in a jar" and a "mountain climber." But , as I pointed out to him, if he wants to seriously run in the South Carolina Republican primary, the committee needs to act quickly. The state's primary is in six days. But while his campaign flounders between fiction and reality, his Super PAC is pouring real money into attack ads that are airing in South Carolina. While I asked him about the PAC-financed attacks- which call Mitt Romney a "serial killer"- like other politicians, Colbert claims ignorance about the content of the ads. Watch George's interview with Colbert: http://abcn.ws/zPkaRS

SANTORUM FRAMES THE WEEK. Presidential candidate Rick Santorum opened the final week of campaigning before voters go to the polls in South Carolina with his strongest assault yet on rivals Mitt Romney and Ron Paul. At an event this morning in Columbia, Santorum said that Romney "has a long track record of sending out his henchmen with the super PAC and his own Political action committee, his own campaign committee to go out and not talk about himself but other than try to spread disinformation.  We've seen Congressman Gingrich talk about how Gov. Romney has lied about his record and that's been documented.  Here we see the frontrunner who is out there with one of the most liberal records in the field, certainly the most liberal record in the field go out and try to tear down other folks instead of talking about what he wants to for this country and run a positive campaign which I have done."

Aides to Santorum told ABC News on Sunday that the former Pennsylvania senator is fed up with the negative attacks coming from the campaigns of those two opponents and from their allies. He will hold a press conference to make his displeasure known after his first campaign event of the day on Monday. "It's time for these negative, false attacks to stop - enough is enough," Santorum's communications director Hogan Gidley said in an interview with ABC News. Gidley complained specifically about mailers and robocalls "bashing Rick and distorting his record" on a variety of issues. http://abcn.ws/zSFioU

DIGGING INTO SANTORUM'S EARMARK RECORD. The New York Times' Michael Luo and Mike McIntire took a closer look at Santorum's record in Congress and found that "the river of federal money" he "helped direct to Pennsylvania paid off handsomely in the form of campaign cash. Earmarks, long a hallmark of a pay-to-play culture in Washington, have become largely taboo among lawmakers of both parties. But that element of Mr. Santorum's record has mostly gone unexplored, in part because transparency rules governing earmarks did not go into effect until after he left office. In just one piece of legislation, the defense appropriations bill for the 2006 fiscal year, Mr. Santorum helped secure $124 million in federal financing for 54 earmarks, according to a tally by Taxpayers for Common Sense, a budget watchdog group. In that year's election cycle, Mr. Santorum's Senate campaign committee and his 'leadership PAC' took in more than $200,000 in contributions from people associated with the companies that benefited or their lobbyists, an analysis of campaign finance records by The New York Times shows. A senior adviser to the Santorum campaign, John Brabender, said Friday that contributions from earmark recipients would 'not have been a factor in any way' in the senator's decision to support their projects, adding that they were a fraction of the more than 100,000 people who gave money to Mr. Santorum's 2006 re-election campaign." http://nyti.ms/zs2NJo

BLACK CHURCH-GOERS CONFRONT GINGRICH. Republican presidential candidate Newt Gingrich faced tough questions Saturday from a predominately black crowd at the Jones Memorial African Methodist Episcopal Zion Church in Columbia, S.C., ABC's Elicia Dover notes. Gingrich received criticism along the campaign trail several times this year for his positions on black teenage unemployment, child labor, the NAACP and food stamps. Gingrich fell into hot water a couple of weeks ago when he said that he would like appear before the NAACP and tell them why they should want paychecks over food stamps. Gingrich said he was referring to the Republican Party's unwillingness to attend such conferences. While the exchanges between the people in the church were mostly respectful, one woman in the crowd, Raushanne Thompson, told Gingrich he was "known throughout the state and throughout the county as a racist and a bigot." "First of all, I don't quite know why you would say that," Gingrich said. "What I've said is that we want everyone to be able to rise in all of America. We want everyone to be able to use English and be able to rise in the whole country. That's the only reference I ever made to the ghetto, was to say that nobody should be trapped without having to use English in order to get a better job." http://abcn.ws/xlBi6D

RON PAUL RETURNS. ABC's Jason Volack reports that Ron Paul on Sunday received the endorsement of South Carolina state Sen. Tom Davis, a state lawmaker popular with tea party activists over the weekend. Speaking at a rally in Myrtle Beach on Sunday, Davis praised Paul's "drastic and radical" efforts to reign in government spending. The Paul campaign described the announcement as "consequential" and "game-changing," adding in a statement that it "virtually assures" that Paul will get the support of fiscal conservatives in the "First in the South" primary. Paul returns to the campaign trail today after taking a three-day break from campaigning to spend time with his family. The congressman predicted earlier in the week that he will finish in the "top tier" in the state's primary Jan 21. http://abcn.ws/wcrsAp

IN CASE YOU MISSED IT: FROM ROMNEY'S WALLET TO HER POCKET. Amid shaking hands and signing campaign posters, Mitt Romney did something he has never done before on the ropeline: He took out his wallet and handed a wad of cash to a woman waiting to shake his hand. As ABC's Emily Friedman reports, it occurred this weekend at a campaign event in Sumter, S.C. The woman, 55-year-old Ruth Williams, said she has been following the Romney campaign since he arrived in the state on Jan. 11, when she said she received a message from God to track him down. "I was on the highway praying and said, 'God just show me how to get [my] lights on,' and I pulled up to a stop sign and his bus was there," said Williams, who has been unemployed since last October. "And then God said, 'Follow the bus,' and I followed the bus to the airport." While Williams would not specify how much money Romney gave her, a campaign spokesman said that he believes Romney gave the woman between $50 and $60. http://abcn.ws/yF9nVq

 

WHO'S TWEETING?

@ TomBevanRCP : Sen. Demint emails: I do not have a favorite in this race and I will not endorse a candidate.

@ MysteryPollster : New Fox News national poll has Mitt at 40, Santorum 15, Newt 14, Paul 13, Perry 6, Huntsman 5  fxn.ws/zjhWAk

@ BuzzFeedBen : Reupping our John Weaver story, for the non- 2am crowd buzzfeed.com/buzzfeedpoliti…

@ davidaxelrod : With '16 in mind, Huntsman backs the man he's called "a perfectly lubricated weather vane," who has "been on 3 sides of every major issue."

@mattklewis : All that is left unfinished is for the Huntsman daughters to get a TV gig?

DISPATCHES FROM THE TRAIL. Check out our new political website OTUSNews.com ( www.Otusnews.com) The Note ( http://abcnews.go.com/blogs/politics/the-note/) and ABC News/Politics ( http://abcnews.go.com/politics) and follow our reporters in the field on Twitter:

Newt Gingrich : ABC's Elicia Dover ( @EliciaDover)

Jon Huntsman and: ABC's Susan Archer ( @TheOnlyArcher)

Ron Paul : ABC's Jason Volack ( @Jason_Volack)

Rick Perry : ABC's Arlette Saenz ( @ArletteSaenz)

Mitt Romney : ABC's Emily Friedman ( @EmilyABC)

Rick Santorum : ABC's Shushannah Walshe ( @shushwalshe) and ABC's Russell Goldman ( @GoldmanRussell)

 

Check out The Note's Futures Calendar:  http://abcn.ws/ZI9gV

 

* Get  The Note delivered  to your inbox every day.

* For breaking political news and analysis check out The Note blog:  http://blogs.abcnews.com/thenote/ and ABCNews.com/Politics:  http://abcnews.com/politics