Charleston, South Carolina (CNN) - With hours to go until the final GOP presidential debate before the Palmetto State's crucial Republican primary, two new polls indicate that Mitt Romney's lead over Newt Gingrich is shrinking.
According to a Politico survey released Thursday morning, 37% of likely South Carolina Republican primary voters say they are backing Romney, with 30% supporting Gingrich. The poll indicates Rep. Ron Paul of Texas at 11%, former Sen. Rick Santorum of Pennsylvania at 10%, Texas Gov. Rick Perry at 4% and 8% undecided.
Tune in Thursday at 8 p.m. ET for the CNN/Southern Republican Presidential Debate hosted by John King and follow it on Twitter at #CNNDebate. For real-time coverage of the South Carolina primary, go to CNNPolitics.com or to the CNN apps or CNN mobile web site.
Follow the Ticker on Twitter: @PoliticalTicker
The poll was conducted Tuesday and Wednesday, after Monday night's presidential debate in Myrtle Beach, South Carolina. Most pundits agree that Gingrich had a strong performance at the debate. At the same showdown, Romney came under attack by his rivals for hedging on whether he would release his tax returns.
The five major GOP candidates face off again Thursday night at the CNN/Southern Republican Presidential Debate at the North Charleston Coliseum. It's the final showdown for the candidates before Saturday's primary, the third contest in the primary and caucus calendar.
Another new poll released Thursday morning also indicates that Romney's lead in the Palmetto State over Gingrich and the rest of the field is shrinking. According to an NBC News/Marist survey, Romney has the support of 34% of likely primary voters in South Carolina, with Gingrich at 24%, Paul at 16%, Santorum at 14% and Perry at 4%.
The NBC News/Marist poll was conducted half before and half after Monday night's debate. Romney had a 15 point lead over Gingrich (37%-22%) after the first night of the poll, but just a 5 point advantage over Gingrich (31%-26%) when looking at only Tuesday's results from the survey.
Both new surveys were released one day after a CNN/Time/ORC International poll that indicated 33% of likely South Carolina Republican primary voters are backing Romney, with 23% supporting Gingrich. The former Massachusetts governor's 10 point advantage over the former House speaker was down from a 19 point lead two weeks ago.
According to the Politico survey, when voters were asked to volunteer the name of the candidate they plan to vote for without being prompted by any list to choose from, Romney's lead over Gingrich slips to 31-29. And among those who say they will "definitely" support their candidate of choice, the two are essentially tied, with Romney at 23% and Gingrich at 22%.
The Politico poll was conducted Jan. 17-18, with 600 likely South Carolina GOP primary voters questioned by telephone. The survey's sampling error is plus or minus four percentage points.
The NBC News/Marist Poll was conducted Jan. 16-17, with 684 likely primary voters questioned by telephone. The survey's overall sampling error is plus or minus 3.8 percentage points, with a sampling error of plus or minus 5.5 percentage points for each individual night of the poll.
The CNN/Time poll was conducted by ORC International from January 13-17, with 505 voters who are likely to vote in the Republican primary questioned by telephone. The survey's overall sampling error is plus or minus 4.5 percentage points.