(CNN) -- Sen. Blanche Lincoln of Arkansas won the Democratic primary Tuesday, beating back a challenge from Lt. Gov. Bill Halter, whose campaign was fueled by unions and liberal activists.
Voters in 12 states held primary elections Tuesday night, but the outcomes of two contests in South Carolina will be delayed by another two weeks. A runoff will be held June 22 for the Republican gubernatorial nomination as well as for a GOP congressional seat in the northern part of the state.
California Republican voters chose two women to vie for two of the state's highest offices: Former eBay CEO Meg Whitman will face Attorney General Jerry Brown, a former governor, for the governor's office, and former Hewlett-Packard CEO Carly Fiorina will take on Sen. Barbara Boxer for her seat.
And in Nevada, Tea Party-backed Sharron Angle beat the GOP establishment candidate to earn the right to take on Senate Majority Leader Harry Reid in November.
At the same time, embattled Nevada Gov. Jim Gibbons, a Republican, became the state's first incumbent governor in 100 years to lose a primary race.
The South Carolina GOP gubernatorial contest captured national attention because of accusations of extramarital affairs.
The candidates are vying to succeed scandal-plagued Gov. Mark Sanford, a fellow Republican. A year after Sanford made national news for disappearing and then admitting to an affair with a woman from Argentina, allegations of infidelity surrounded state lawmaker Nikki Haley.
Haley has denied the accusations over the last two weeks, which she said rival campaigns were pushing.
Haley cruised to a commanding lead but fell short of the 50 percent threshold needed to avoid a runoff election, scheduled for June 22. She'll face U.S. Rep. Gresham Barrett, who came in at a distant second.
"You saw us push against the establishment and push against the money and push against the power," Haley said at her election-night celebration in Columbia, South Carolina. "And boy did they push back."
Haley told supporters, "Over the last two weeks, we said no to the dark side of politics."
In California, Whitman topped Steve Poizner in the gubernatorial primary.
Whitman, who also was an adviser and surrogate for Sen. John McCain's 2008 presidential bid, spent around $70 million of her own money in the race. Poizner, California's insurance commissioner and a self-made multimillionaire, injected some $25 million of his money into his campaign.
The winner in November will succeed Republican Gov. Arnold Schwarzenegger, who can't seek re-election because of term limits.
Fiorina easily won the Republican Senate primary, and polls suggest that Boxer faces a tough re-election battle.
In neighboring Nevada, Reid also is considered vulnerable in November. A crowded field of 13 Republicans were competing for a chance to challenge the Senate majority leader in his bid for a fifth term in the Senate.
Angle, a former Nevada Assembly member, won endorsements from many conservative organizations, including significant financial backing from the Tea Party Express, a national Tea Party group best known for running cross-country bus caravans, and the Club for Growth, a fiscally conservative organization.
Gibbons' loss makes him the first incumbent governor to lose a primary this year. Former federal Judge Brian Sandoval won the state's GOP gubernatorial contest.
In Arkansas, Lincoln was able to survive a primary runoff despite an anti-incumbent wave, but she'll face a tough general-election fight against Rep. John Boozman, the GOP nominee.
"We've got a lot worth fighting for. A whole lot worth fighting for. We're going to make sure, as we regroup tomorrow, we put this campaign on a trajectory toward November and a victory in November," Lincoln said after the results came in.
Iowa, Maine, Montana, New Jersey, North Dakota, South Dakota and Virginia also held primaries Tuesday. Former state Rep. Tom Graves, a Republican, won the runoff in Georgia to fill the seat of former Rep. Nathan Deal. Deal, also a Republican, stepped down this year to run for Georgia governor.
CNN's Kevin Bohn, Peter Hamby, Kristi Keck, Mark Preston, Charles Riley and Paul Steinhauser contributed to this report.