Newt Gingrich's "suicidal" "kamikaze" "jihad" against Mitt Romney looks like it wasn't so suicidal after all. Gingrich got many thumbs up for his debate performance Monday, but there wasn't any evidence he could turn that -- or his populist attacks on Romney -- into votes. But now there is a bit of data: Romney's lead in South Carolina has shrunk by half. Here's our guide to today's polls and why they matter.

Findings: Romney's lead over Gingrich has been cut almost in half in South Carolina in the last two weeks. He now leads the former House speaker 33 percent to 22 percent. 
Pollster: CNN/ Time/ ORC
Methodology: Phone calls to 505 likely voters in the South Carolina primary January 13 to January 17.
Why it matters: There has been speculation about a Gingrich surge since he got a standing ovation at the Fox News primary debate Monday. But so far, all evidence was anecdotal, NBC News' First Read wrote Wednesday morning, like that Sarah Palin quasi-endorsed Gingrich, and that Romney's campaign is nervous enough to hold a conference call with two of Gingrich's former congressional colleagues bashing Newt. Now we have one little data point.
Caveat: The poll spans several days, only one of them after Gingrich's performance in the debate. "Much buzz about Newt on ground here since," Politico's Jonathan Martin tweets.

Findings: Mitt Romney has the support of 40 percent of moderate primary voters, but only a quarter of conservative primary voters' support. Gingrich and Santorum both get 25 percent of conservatives' votes.
Pollster: New York Times/CBS News
Methodology: Phone survey of 1,154 voters, 340 of them likely Republican primary voters, from January 12 to January 17. 
Why it matters: In the New Hampshire primary, Romney won the conservative vote for the first time. But this poll shows he hasn't won conservatives over nationally. And a Pew poll finds Tea Party Republicans back Gingrich over Romney 42 percent to 43 percent. So it looks like there are still a lot of voters open to another candidate.
Caveat: You can say 75 percent of conservatives want someone other than Romney, but you can say that about Gingrich and Santorum, too. The New York Times' Nate Silver calls the "Anybody but Romney" meme a myth, because, "If you look beyond the top-line data in the polls, it becomes clear that nowhere near 75 percent of Republican voters have been vehemently opposed to nominating Mr. Romney."

Findings: A third-party candidacy by Ron Paul would really hurt Romney. If the choice is between Obama and Romney, the vote is 50 percent of 45 percent, but if Paul's thrown in there, the vote is Obama's 44 percent to Romney's 32 percent to Paul's 18 percent.
Pollster: Pew Research Center
Methodology: Phone interviews between January 11 and January 16 with 1,207 registered voters, 527 of them Republican or Republican-leaning.
Why it matters: Paul has said he won't run as an independent, but there's some debate over whether his denials leave him some room to change his mind. And a lot of Paul's supporters are young people who don't like the wars overseas -- potential Obama supporters. But Pew finds Paul wouldn't pull many of those kids from Obama: "Where [Paul] would  appeal to 30% of Republicans and Republican leaners under age 45, he would draw the backing of just 12% of Democrats and Democratic leaners in the same age range," the pollster says. 
Caveat: Paul fans have a long time to change their minds (as does Ron Paul).