Never bet against a candidate named Lincoln.

Tuesday night's so-called "Mini-Super Tuesday" of major primaries in 12 states showed that the only thing that will be predictable about the 2010 elections will be their unpredictability.

Written off for dead by most political pundits, centrist Arkansas Democratic Sen. Blanche Lincoln surprised the experts by narrowly defeating challenger Bill Halter, whose candidacy was seen as a test of how well a liberal, union-backed insurgent could do in the Deep South.

Lincoln - a two-term incumbent - was backed by the party establishment, including the rock star of Arkansas politics, ex-President Bill Clinton, as well as a majority of black voters.

Halter, the Razorback State's lieutenant governor, was backed by a coalition of unions and liberal groups, such as MoveOn.org, that felt betrayed by Lincoln's failure to support a public option for health insurance or a so-called "card check" for labor organizing.

Larry Sabato, the University of Virginia history professor and political pundit, said that low turnout in the primary season has amplified the importance of partisan ideologues, which is why the relatively liberal Halter even had a chance in such a conservative state. "It's a low-turnout election, and you have a lot of activists," he said.

Lincoln blamed her political struggle on her willingness to find common ground, telling reporters in Little Rock, as quoted by Politico: "You've got one side in their foxhole and the other side in their foxhole. There are very few to come out into the battlefield and stand up and say, 'Where's the common ground? How do we solve these problems?' "

Her victory came despite a new survey showing that an angry electorate, roiled by nearly double-digit unemployment and an environmental catastrophe in the Gulf of Mexico, is more inclined than at any time in recent memory to vote incumbents out of office.

The Washington Post-ABC News poll found that only 29 percent of Americans want to see their own members of the House of Representatives reelected, lower than in 1994 when a GOP landslide flipped control of Congress.

During the primary season, voters ousted four congressional incumbents before last night, and in three of those cases their replacements came from the more extreme wing of either party.

Meanwhile, on the Republican side, it looked like a good night again for the more conservative Tea Party faction of the GOP.

In Nevada, the favorite daughter of Tea Party activists - state lawmaker Sharron Angle - was building an insurrmountable lead against two rivals more tied to the party establishment. Some have compared Angle - who has advocated eliminating the U.S. Environmental Protection Agency and privatizing Social Security and has ties to the radical Oath Keepers - to libertarian Kentucky Senate candidate Rand Paul in her knack for taking extreme and unorthodox positions.

Also in Nevada, incumbent Gov. Jim Gibbons, plagued by multiple scandals including alleged adultery, was overwhelmingly defeated.

In fact, Lincoln's win was one more sign that in a year of anti-incumbent fervor and other factors, political circumstances have boosted the political fortunes of female candidates, perhaps even more so than in the so-called "Year of the Woman" in American politics in 1992.

That was especially true in California, where two well-known female high-tech entrepreneurs were on track to capture the top two slots on the Republican ticket.

In the race to succeed Gov. Arnold Schwarzenegger in Sacramento, the former CEO of eBay, Meg Whitman, won the GOP nod to oppose former Democratic Gov. Jerry Brown. Likewise, former Hewlett-Packard boss Carly Fiorina was victorious in her Senate primary in the Golden State to oppose incumbent Sen. Barbara Boxer in November.

Another woman who overcame adversity was South Carolina Republican gubernatorial candidate Nikki Haley, who won more votes than three male opponents to gain a runoff despite allegations - which she strongly denied - of extramarital affairs with two male GOP activists, as well as an episode in which a well-known pol labeled her "a raghead" because of her Sikh ancestry.