(CNN) -- Newt Gingrich's stunningly strong win in the South Carolina primary capped an incredible week in the Republican presidential nominating cycle., but what did we learn from it?
Endorsements matter little
Two-thirds of Republicans who voted Saturday approved of South Carolina Gov. Nikki Haley's job performance, exit polls showed.
Haley endorsed former Massachusetts Gov. Mitt Romney in December and campaigned aggressively for him across the state down the final stretch. However, the general goodwill that Republicans have toward their governor made little impact on the race.
Voters who approved of Haley went for Gingrich. Voters who disapproved of Haley went for Gingrich, too.
Though endorsements are great for generating media coverage and conveying a sense of credibility, they ultimately mattered little in the South Carolina race.
Gingrich proved it, handily winning the primary without many big names behind him, aside from state House Speaker Bobby Harrell who only backed Gingrich after the Republican he had previously supported, Texas Gov. Rick Perry, dropped out of the race.
Meanwhile, one-time candidates like Perry and Jon Huntsman stumped through South Carolina touting their endorsements from well-known state legislators and state Republican icons.
Neither man made it to Election Day.
Moderates love Mitt
Romney didn't win much on Saturday, but he did win moderates.
Exit polls showed that voters who identified themselves as "moderate or liberal" went for Romney. "Conservative" and "very conservative" Republicans, meanwhile, voted for Gingrich.
The demographic groups that Romney did win, according to the exit polls, are not exactly the ground troops of the Republican base.
Voters opposed to the Tea Party movement? Romney won 'em. Voters who have attained some level of postgraduate education? Romney won 'em. Voters who think abortion should be legal? Romney won 'em.
Romney's distant second-place finish Saturday raises questions about his ability to win over conservatives in the South -- the beating heart of the Republican Party -- if he eventually wins the GOP presidential nomination.
Did we say debates do matter?
The GOP presidential showdowns have been the storyline of the cycle, with the debates seemingly more influential than retail politics, early organization, campaign cash, and campaign advertising.
It appears that strong performances by Gingrich in this past week's two debates in the Palmetto State were crucial in helping the former House Speaker erase Romney's lead in the public opinion polls and storm back to win the South Carolina primary.
According to exit polls of people who voted in the GOP presidential primary, 65% said the debates were important to their vote, with Gingrich winning those people by a more than 2-1 margin over Romney.
Need more proof? Fifty-five percent said they decided in the last few days and Gingrich won those voters by a 2-1 margin over Romney.
With two debates next week in Florida ahead of the state's January 31 primary, expect the debate storyline to continue.
Here we go again
Maybe the marathon primary battle between Barack Obama and Hillary Clinton in 2008 wasn't a fluke. Gingrich's strong double-digit victory in South Carolina ensures that the battle for the GOP presidential nomination will at least go through Super Tuesday on March 6.
If Gingrich can survive Florida and the February contests (which right now favor Romney), Super Tuesday provides more friendly territory.
If Rick Santorum runs out of steam over the next couple of weeks, Gingrich would become the final conservative alternative to Romney.
Rep. Ron Paul of Texas said Saturday despite a fourth-place finish in South Carolina, he has no intention of giving up, which means this GOP race could last into the spring.
Get ready for a nastier battle ahead
You think the South Carolina primary was rough, imagine what the next 10 days before the Florida primary will be like.
Romney signaled that he was throwing down the gloves in his "concession" speech Saturday night. After congratulating Gingrich on his win, Romney accused him of the same kind of class warfare that Republicans accuse Obama of -- Gingrich wielding the "weapons of the left" to bring him down.
"If Republican leaders want to join the president in demonizing success and disparaging conservative values then they're not going to be fit to be our nominee."
If you live in Florida and are turned off by negative ads, consider a 10-day vacation to a colder climate. Romney's campaign and the super PACs that support him have millions of dollars to saturate Florida airwaves with attack ads of the same ilk.
After trying to appear as the presumptive nominee, Romney tried to reverse field and go on the attack against Gingrich to stop his momentum before Saturday, but probably too late. His Saturday night speech signals that he knows he's in a fight.