Gingrich atop poll of Republican voters in Mississippi

UPDATED 1:58 p.m. ET

(CBS News) Former House Speaker Newt Gingrich is leading Mitt Romney in the latest poll of likely Republican primary voters in Mississippi, where voters head to the polls Tuesday to choose the candidate they want to take on President Obama in November.

Gingrich garnered 35 percent support in Mississippi, compared to Romney's 31 percent in a poll released Friday by American Research Group, Inc. Former Pennsylvania Sen. Rick Santorum took 20 percent while Texas Rep. Ron Paul received just 7 percent.

Gingrich, who won his home state of Georgia three days ago, has said Mississippi and Alabama are must wins for his campaign, which is floundering behind front-runner Romney and Santorum.

Santorum defeated Gingrich in Tennessee on Super Tuesday, which Gingrich had also hoped to win to jumpstart his candidacy which had not had a win since late January when he won the South Carolina primary.

The Gingrich campaign said it was spending slightly more than $200,000 combined in Mississippi and Alabama on television ads to build support ahead of Tuesday's contests.

Among men, Gingrich has nearly double the support of either Romney or Santorum, according to the poll. Gingrich took 39 percent of men compared to 21 percent each for Santorum and Romney.  Among women, Romney leads Gingrich 42 percent to 30 percent, followed by Santorum's 19 percent and Paul's 2 percent.

Among those who identify with the conservative Tea Party wing of the party, Gingrich took 49 percent, more than twice Romney's 24 percent support. Santorum took 17 percent of the tea partiers and Paul just 5 percent.

The telephone poll of 600 likely Republican primary voters living in Mississippi was conducted March 7 through March 8 and has a margin of error of plus or minus 4 percentage points.