The exit polls out of South Carolina were pretty fascinating.

Exit poll results found that nearly two-thirds of Republican primary voters called the debates important to their vote, and they favored Gingrich over Romney by a vast 50-22 percent. More than half of voters also decided in just the last few days — more than in either Iowa or New Hampshire — and they likewise went overwhelmingly for Gingrich, by a 22-point margin over Romney, 44-22 percent.

Gingrich’s persuasiveness in the debates helped push him to an advantage even in electability, previously Romney’s strong suit. Forty-five percent of South Carolina voters were focused chiefly on the candidate who’s best able to defeat Barack Obama in November — and these voters favored Gingrich over Romney by a 14-point margin, 51-37 percent.

That last point was of particular interest. One of the key messages from the Romney campaign — sometimes explicit, sometimes implicit — is that GOP voters should focus on electability, arguably to the exclusion of every other consideration. But in South Carolina, Republicans did exactly that, and they heavily preferred Gingrich.

That’s an edge Romney simply can’t afford to lose. If the party’s base begins to see Gingrich as the stronger contender for November — better debater, clearer contrasts, better able to generate enthusiasm among conservatives — that will only make Romney’s task that much more difficult.

Here’s another data point that’s worth keeping an eye on:

The controversy over Romney’s experience at Bain Capital may have done him some damage as well. While almost two-thirds saw his work there positively, a not-insubstantial 28 percent saw it as a negative — and among these voters Romney had essentially no support — 3 percent, to Gingrich’s 50. Skeptics of his experience at Bain disproportionately included lower-income voters, as well as those focused on moral character.

You’ll recall that the focus on Romney’s controversial private-sector background began in earnest shortly before the New Hampshire primary. When the former governor won that primary easily, Romney aides said he’d effectively been inoculated — if Bain was damaging, we would have seen it in the N.H. results.

But that spin was, at best, incomplete. The story was still quite new when Granite State voters went to the polls, and the issue was less likely to resonate in New Hampshire anyway. It’s a stretch to think Bain was the deciding factor in Romney’s poor showing yesterday, but as the exit polls suggest, it didn’t do him any favors — and we’re getting a hint about the kind of voters who may consider the issue relevant as the process moves on.

Ultimately, though, the top three most important factors in South Carolina were the debates, the debates, and the debates. By the time he’d received his second standing ovation in Thursday night’s debate, it was hard to not think, “You know, maybe Newt is going to win this primary after all.” Back in October, the Romney campaign adopted a strategy predicated on the belief that the debates really do matter. They were right.

Gingrich used these forums to play to the worst instincts of his party’s right-wing base, aiming right at the Republican id — presenting himself and his party as victims, condemning the media, and adding some not-so-subtle racial politics to connect with South Carolina Republicans on a gut level. As I mentioned the other day, Gingrich’s debate performances are like dopamine for the right-wing soul.

His next challenge: duplicating the efficacy of this strategy elsewhere.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.