Story highlights

Rick Santorum scores a stunning victory by almost upsetting Mitt Romney

Romney wins the Iowa caucuses in a tight race, besting Santorum by eight votes

It is an uphill battle for Santorum, who faces a better-funded rival in Romney

Program notes: John King talks with Rick Santorum about his surge in the polls, his strong showing in the Iowa caucuses and how he plans to continue the momentum at 6 p.m. ET Wednesday on “John King, USA.”

(CNN) —  

With a narrow loss, Rick Santorum scored a stunning victory and now heads to New Hampshire, hoping this momentum sets him up as the anti-Mitt Romney in the race for the Republican presidential nomination.

Santorum, who lost to Romney by eight votes in the Iowa caucuses early Wednesday, is following a well-worn path on his march as the new political battleground shifts from this Midwestern state to New Hampshire.

It is an uphill battle for Santorum, who faces a better-funded rival in Romney and questions about his own viability as a general election candidate.

Meanwhile, one-time leading contender Newt Gingrich is hoping to breathe new life into his campaign with a sharper message in a new state. Rick Perry, who came in a disappointing fifth in the caucuses, said he was heading back to Texas to “reassess” his campaign, a statement that all but seems to close the book on his presidential bid that took off like a rocket in August only to fall out of the sky in the ensuing months.

Perhaps, the second biggest surprise of the night – nothing can match the razor-thin margin that Romney won by – was Michele Bachmann’s refusal to bow out of the race even though she came in a disappointing sixth place.

She is scheduled to appear in South Carolina on Wednesday – hoping to open up a second front in the battle for the Republican nomination. For Bachmann, New Hampshire is not an option to restart her campaign, as her fate rests with the influential evangelical/born-again voters in South Carolina – the same group that failed to rally behind her in Iowa.

Even though Ron Paul came in third, he should get credit for building a strong ground game. Paul has proven he is an effective campaigner with a loyal following. He is not going anywhere, anytime soon.

Romney is heavily favored to win the New Hampshire primary and it should come as no surprise that he will take time this week to campaign in South Carolina – a political strike to try and suppress any momentum that might be building for Santorum or support for Gingrich.

Santorum will press hard for South Carolina’s evangelical/born again voters on January 11, but he is not willing to cede this valuable opportunity to draw a spotlight onto his campaign. A wealthy candidate, such as Romney, has the ability to pick and choose what states to play in. Santorum is no Romney when it comes to money, staff and resources.

“We are not just going to compete where we think we can win,” said John Brabender, Santorum’s senior strategist. “We think we are the best alternative to Mitt Romney and we are willing to go right into his backyard.”

The race for the 2012 GOP nomination, which has largely been an exercise in retail politics over the past few weeks, takes on the added dimension of a national campaign – which largely defined the race for most of the year. This weekend, the candidates will appear in two nationally televised debates – a setting that befits Newt Gingrich, who came in 4th place last night. Gingrich’s steady performance in the dozen-plus presidential debates helped fuel his rise in the polls in December only to come quickly crashing down under the barrage of negative advertising.

“This weekend’s debates are a big deal,” said David Winston, a veteran Republican strategist who is advising Gingrich. “This will be the first time the candidates will have been together since early December.”

Winston said he had never seen such a massive amount of negative television advertising directed at a presidential candidate as what Gingrich has endured over the past month.

“If you are trying to change the general narrative, this is where the folks are going to be,” Winston said of New Hampshire.

After New Hampshire, the next stop in the battle for the GOP nomination is January 21 in South Carolina, followed by Florida on January 31.

While Romney is likely to win New Hampshire, a big, strong showing by Santorum or Gingrich will determine whether this race comes to a quick close on Super Tuesday or continues on into the spring.

And then there is Jon Huntsman, is there any chance he will be able to soak up some of the spotlight that will now shine brightly on New Hampshire.