Three new polls show former House Speaker Newt Gingrich gaining on Mitt Romney in South Carolina and emerging as the clear conservative choice of voters who are not backing the former Massachusetts governor for the Republican presidential nomination.

An Insider Advantage/Majority Opinion Research survey completed on Thursday shows that Gingrich is actually in a statistical tie with Romney in South Carolina, with 21.3 percent of the vote to Romney’s 23.1.

Gingrich leads Romney in several demographic groups, including voters 18 to 29 years old, black voters, male voters, and Independents.

Ron Paul and Rick Santorum each received 13 percent of the vote.

The latest Rasmussen Reports poll of likely Republican voters in South Carolina finds Romney ahead with 28 percent of the vote, but Gingrich has moved into second place with 21 percent. Santorum had been in second a week ago, but has now fallen back to 16 percent, dead even with Paul.

And an American Research Group (ARG) poll completed Thursday shows that Gingrich has closed the gap with Romney to just four points in South Carolina. Romney drew 29 percent of the votes, down from 31 percent a week earlier, while Gingrich rose from 24 percent to 25 percent. Santorum, meanwhile, plunged from 24 percent to just 7 percent, and Paul now has 20 percent of the votes.

The ARG survey also found Gingrich leading Romney among voters who say they are supporters of the tea party, 28 percent to 24 percent. Among evangelical Christians, Gingrich gets 40 percent of the vote, followed by Rick Perry with 15 percent, Romney with 13 percent, Santorum with 12 percent, and Paul at 10 percent.

That poll also shows that Paul has overtaken Romney as the favorite among Independents, beating Romney by a margin of 29 percent to 27 percent.