(CNN) -- Voters in four states head to the polls Tuesday, and in one of those states history might be made:
South Carolina Republicans could make state Rep. Nikki Haley their first female gubernatorial nominee. She's in a runoff against U.S. Rep. Gresham Barrett.
Haley just missed out on winning the nomination outright in the June 8 primary, capturing 49 percent of the vote in a four-candidate field. She was short of the 50 percent plus one needed to take the nomination.
Once facing long odds for the GOP nomination, Haley rose in the polls thanks in part to endorsements by former Massachusetts Gov. Mitt Romney and former Alaska Gov. Sarah Palin.
And unsubstantiated allegations by two other Republicans that they had affairs with Haley, who is married with children, most likely helped rather than hurt her campaign. So did a racial slur by a Republican state lawmaker at Haley, who is Indian-American and was raised Sikh, but became a Methodist at age 24.
"The unproven allegations and attacks against Haley actually played right into her message as a new kind of conservative," said CNN political producer Peter Hamby, who is in South Carolina reporting on the campaign.
"In fighting back, she was able to argue that establishment figures in the GOP were playing politics as usual and trying to stop a real reformer from taking charge in Columbia."
If Haley wins Tuesday's runoff, she'll be considered the favorite in the general election against state Sen. Vincent Sheheen, the Democratic gubernatorial nominee. Haley would become the Palmetto state's first woman governor if elected in November.
There are also runoffs in South Carolina in contests for the House of Representatives and for the state Legislature. State Rep. Tim Scott hopes to become the first black Republican to win election to Congress from South Carolina in a century. He faces off against Paul Thurmond, the son of the late Sen. Strom Thurmond, in a GOP House primary runoff.
Republican Rep. Bob Inglis is hoping he won't become the third House incumbent to lose a bid for re-election so far this primary season. He grabbed 27 percent of the vote in the primary and now faces a runoff against Spartanburg prosecutor Trey Gowdy. Inglis is facing criticism for his vote in favor of the Troubled Asset Relief Program, or TARP, better known as the Wall Street bailout.
In neighboring North Carolina, Secretary of State Elaine Marshall faces off in a Democratic Senate primary runoff against former state Sen. Cal Cunningham, who was recruited by national Democrats. The winner will challenge Republican Sen. Richard Burr in November's general election.
"Richard Burr doesn't have the strongest poll numbers, but that may not matter," said Stuart Rothenberg, publisher and editor of the nonpartisan Rothenberg Political Report.
Rothenberg said neither of the Democratic candidates "seems likely to put together the kind of campaign that would defeat Burr."
Voters in three congressional districts and one state Senate district also will cast ballots in runoff contests.
Two Republicans are in a runoff to decide who will face eight-term incumbent Rep. Bennie Thompson in November in Mississippi's 2nd Congressional District.
Richard Cook, a Jackson-area teacher, finished a single vote ahead of Bill Marcy, a former Chicago, Illinois, police officer, in the state's June 1 primary, with each getting 35 percent of the vote in a three-candidate field.
Cook lost in his 2008 bid to unseat Thompson, who chairs the House Homeland Security Committee, with Thompson getting 69 percent of the vote.
The fight for the GOP Senate nomination is capturing the spotlight in Utah, and the contest will be another test of the political strength of the Tea Party Express.
The national Tea Party group, which is based in California, is backing and assisting lawyer Mike Lee in the battle to succeed fellow Republican Bob Bennett, who is supporting the other candidate on the ballot, businessman Tim Bridgewater.
Bridgewater and Lee finished first and second, respectively last month at the Utah Republican Party convention, advancing to Tuesday's primary. Bridgewater and Lee touted themselves as more reliable conservatives than Bennett, who finished third in the voting by delegates, eliminating him from advancing to the primary and ending his chances of re-election for a fourth term. Bennett became the first sitting senator to go down to defeat in a primary season marked by strong anti-incumbent sentiment.
The Tea Party Express, best known for its three national bus tours, is running radio ads supporting Lee. The group recently pumped more than $500,000 into the recent fight for the Republican Senate nomination in Nevada, helping transform ex-state lawmaker Sharron Angle, once considered a long shot, into an easy winner in this month's primary election.
FreedomWorks also has endorsed Lee, and its volunteers are assisting in get-out-the-vote efforts in Utah. FreedomWorks is a nonprofit conservative organization that helps train volunteer activists and has provided much of the organizational heft behind the Tea Party movement.
Bennett upset many conservatives with his 2007 vote for President Bush's plan for a pathway to citizenship for some illegal immigrants and his 2008 vote for the federal bailout of banks and financial institutions. The fiscally conservative Club for Growth actively worked to defeat Bennett, as did local Tea Party organizations and Tea Party Express.
The GOP dominates statewide elections in Utah, and the winner of the Republican primary will be considered the overwhelming favorite to win the general election in November.