Romney struggles to hold off Gingrich Mitt Romney is struggling to hold on to the mantle of inevitable Republican presidential nominee as South Carolinians prepare to cast votes in their primary election on Saturday, with the latest polls giving rival Newt Gingrich the advantage. The former Massachusetts governor had until this week looked like he was destined to win the Republican ticket to challenge Barack Obama in this November's general election, but a deluge of negative news has thrown that into doubt. "Clearly, it's close enough that one could see either Gingrich or Romney winning" on Saturday, said Charles Bierbauer, a veteran of presidential races who teaches at the University of South Carolina. "If it's a difference of only two or three points, that will give Gingrich the impetus to go forward and say: "Look how much I've closed the gap."" Three new polls put Mr Gingrich ahead of Mr Romney in South Carolina. A survey by Public Policy Polling released on Friday put the former House speaker ahead with 35 per cent support, while the former Massachusetts governor trailed with 29 per cent. Gallup on Friday released a poll showing that Mr Romney's lead over Mr Gingrich in its national surveys has fallen sharply. At the beginning of the week, Mr Gingrich was running 23 percentage points ahead of his rival, but that has now narrowed to only 10 points. Mr Romney is the preferred candidate of 30 per cent of likely Republican voters across the country, while Mr Gingrich has 20 per cent support. Mr Gingrich also received a boost from Sarah Palin, the former vice-presidential candidate and darling of the conservative right, who said she would vote for him if she was in South Carolina. That could bolster Mr Gingrich's support among the Tea Party movement. At midday eastern time, Intrade, the political betting site, gave Mr Gingrich a 61.5 per cent chance of winning the primary, against 37 per cent for Mr Romney. The South Carolina primary is the first southern state to vote and has a strong record of backing the eventual nominee. It also has more delegates who will vote for the nominee at the Republican convention than Iowa and New Hampshire, the first two voting states, combined. The state primary is also famous for being one of the most vicious in the country. It was here eight years ago that anonymous fliers claimed that John McCain had an illegitimate black daughter - in fact, the McCains had adopted a Bangladeshi girl. While the final days of campaigning have not plumbed those depths, there have been explosive new allegations about Mr Gingrich's marital history and new pressure on Mr Romney to release his tax returns. During a debate televised on CNN on Thursday night, Mr Romney again equivocated over whether he would release his tax returns, saying he would "probably" release his filings from 2011 as well as previous years "when my taxes are complete for this year and I know if I'm the nominee." His response attracted some booing from the audience. John Sununu, a former governor of New Hampshire who is supporting Mr Romney, admitted that it now looked unlikely that the candidate would be able to sew up the nomination early. "This is a long slog," he told CNN. We need 1,143 delegates in order to win the nomination. Governor Romney is ready to take this forward. But voters in socially conservative South Carolina could also find new reason to doubt Mr Gingrich's character. Marianne Gingrich, the former House speaker's second wife, on Thursday night claimed that her husband divorced her after she would not agree to have an "open marriage." Mr Gingrich used a question about the allegations in Thursday's debate to launch in to a tirade against the "elite media." "I think the destructive, vicious, negative nature of much of the news media makes it harder to govern this country, harder to attract decent people to run for public office," Mr Gingrich told John King, the debate moderator, when asked about the allegations. Jeffrey Peake, a professor of political science at Clemson University, said: "The infidelity stuff is not new for Gingrich, and if people are going to question his character, they were probably already doing it." Mr Romney has also had some good news, picking up endorsements on Friday from Bob McDonnell, the governor of Virginia, and three House members from Texas who previously supported Rick Perry until he dropped out of the race this week. Similarly, Mr Gingrich has had some blows. His campaign cancelled a planned appearance at the Southern Republican Leadership Conference on Friday morning after only two dozen people showed up.