Nikki Haley in South Carolina runoff

South Carolina's Nikki Haley entered a runoff for the Republican gubernatorial primary with a substantial edge over her GOP rival, deflecting attacks on her marriage and her ethnicity using an antiestablishment message that resonated with the state's voters.

"We saw us push against the establishment, we saw us push against the power and push against the money and boy did they push back," Haley, a three-term state lawmaker and tea party headliner, said after coming close to winning the four-way race outright.

Hoping to become the state's first female nominee for governor from a major party, Haley captured 49 percent of the vote to U.S. Rep. Gresham Barrett's 22 percent. A majority of the vote was needed to avoid the June 22 runoff.

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The winner will face state Sen. Vincent Sheheen, a Democrat who won his party's primary over two rivals.

Haley told supporters gathered in the state capital that the label "Republican" isn't good enough and needs to be backed by true conservative action.

"South Carolina was settling for a Republican House, a Republican Senate and a Republican governor, I won't stop until we get a conservative House," she said as supporters cheered.

Within an hour of Haley's speech, the head of the Republican Governors Association proclaimed her the party's nominee in a statement that failed to acknowledge Barrett, a three-term congressman.

"The voters of South Carolina made a clear choice in Nikki Haley, notwithstanding the possibility of a runoff. The outcome is all but certain," said Executive Director Nick Ayers. "Moreover, receiving half of the votes against two other statewide incumbent Republicans and a sitting Congressman speaks volumes of her strength as a candidate and bodes very well for her in the General Election."

The statement was a quick indicator of the pressure Barrett may face to bow out of the contest, but Barrett said Wednesday he is "absolutely" staying in the race.

"That is not even a question in my mind," he added.

Barrett campaign consultant Terry Sullivan said it was the Washington-based group that should back away from the race.

"As much as people from South Carolina appreciate folks from Washington, D.C., telling us how we need to do things down here, we've got a race to run," Sullivan said. "It's a two-week-long runoff."

Haley's achievement comes a year after outgoing, term-limited Republican Gov. Mark Sanford embroiled the state in scandal by admitting to skipping out of the country to rendezvous with his mistress in Argentina.

She was unaffected by unproven claims of affairs leveled by a political blogger and by a lobbyist who worked for a rival campaign.

"The one thing we noticed, we were 'Nikki Who' about six weeks ago. And then all of a sudden it showed we had double-digit lead in the polls, and then we had everything but the kitchen sink thrown at us. And our opponents got together, they threw as much distractions as they could, but we stayed very determined," Haley said Wednesday on ABC's "Good Morning America."

Shortly after those accusations, which she denied, the married mother of two also had to face being called a "raghead" — a derogatory term for people of Middle Eastern or Indian descent — by one opponent's backer. The daughter of Sikh immigrants, she would be the nation's second governor of Indian-American descent.

Haley knocked South Carolina's attorney general and lieutenant governor out of a race for which they'd been preparing for years. It was Lt. Gov. Andre Bauer's backer who used the slur.

Haley blamed an entrenched "Good Old Boy" system for conspiring to derail a campaign that gained steam with a slew of television ads and a spirited endorsement by former Alaska Gov. Sarah Palin. She pivoted off the claims to underscore an antiestablishment message that has so far resonated.

Haley's politics are familiar to the state's conservative voters. She hews to the Libertarian, limited government policies favored by Sanford, though she distanced herself from him. He backed her candidacy and she won the endorsement of his ex-wife, popular former first lady Jenny Sanford.

Related:

• Blanche Lincoln in surprise win in Arkansas; GOP women triumph, too
• Nikki Haley: Fresh face for South Carolina or more of the same?

IN PICTURES: Notable women in US politics