In a surprise move, Alaska Governor Sarah Palin on Friday said she was stepping down and would not seek re-election, fueling swift speculation of a possible 2012 White House bid.
Palin, who was Republican John McCain's running mate in his failed 2008 presidential campaign, said she would step aside as governor and would be replaced by Lieutenant Governor Sean Parnell at the end of July.
Palin, 45, told a press conference at her lakefront home in Wasilla, Alaska, that she wanted to "take a stand and effect change, not just hit our head against the wall and watch valuable state time and money, millions of your dollars, go down the drain."
A former sports journalist known as "Sarah Barracuda" when she played high school basketball, Palin said it was "time to pass the ball for victory."
In leaving her post before the end of her first term, Palin, the first woman to stand on a Republican presidential ticket, will be able to travel across the country more freely and build up a national political team, clearing the way for a potential presidential bid of her own.
A June 2 CNN poll had Palin running neck-and-neck with former Massachusetts governor Mitt Romney and ex-Arkansas governor Mick Huckabee in the top three favorites to head up the Republican 2012 ticket.
While hinting at broader ambitions, Palin also lamented what she called a "superficial, wasteful, political bloodsport."
Staying in power as a lame-duck official after deciding not to run for re-election "would just be another dose of 'politics as usual,' something I campaigned against and will always oppose," she added, insisting her decision "has been in the works for quite a while."
The announcement came as a complete surprise to Alaskans, including members of her own cabinet. "Frankly, we didn't know about it 'till we got out there," Alaska Department of Revenue Commissioner Pat Galvin told AFP. "It was pretty shocking. It wasn't anything I was expecting to hear."
Republican strategists were also caught aback by the sudden move. "It's an enormous gamble -- but it could be a shrewd one," Bill Kristol, a conservative political analyst and editor of the Weekly Standard, wrote on his magazine's website.
"Haven't conservatives been lamenting the lack of a national leader? Well, now she'll try to be that. She may not succeed... She'll be under intense and hostile scrutiny, and she'll have to perform well."
Republican strategist John Weaver told The Washington Post that "if this is about running for president, it's about as odd a way as we've ever seen."
Palin has only led the vast, oil-producing northwestern state since December 2006, when she became the youngest person ever to hold Alaska's governorship.
As governor, Palin has earned approval ratings as high as 80 per cent, but her popularity dipped in the wake of a series of ethics complaints and her failed run with McCain.
The 2008 presidential race saw her ascend overnight from the obscure governor of Alaska to McCain's running mate and her party's popular, but polarizing new cheerleader.
The ex-beauty queen, moose hunter and mother of five wooed conservative Americans by weaving together traditional values and dazzling telegenics, energizing the Republican Party's base. Palin drew massive Republican crowds but also fueled a backlash from Democrats and Independents against herself and McCain.
While she has cast herself as an anti-corruption star, Palin was found to have violated state ethics rules governing public officials. A state troopers union brought an ethics complaint against Palin, alleging she and other officials had disclosed confidential information on her former brother-in-law, Mike Wooten, and systematically sought to fire him.
Earlier this week, the Anchorage Daily News reported that the ethics complaint against the governor and other senior officials from her administration had cost the state personnel board nearly 300,000 dollars, the bulk of it from the "Troopergate" investigation.
"I cannot stand here as your governor and allow the millions of dollars and all that time go to waste just so I can hold the title of governor," Palin said. Palin, the Daily News said, has reportedly spent over 600,000 dollars in personal legal bills to fight the accusations.
Despite a series of blunders in high-profile interviews during the presidential campaign, the governor retains star power in the battered Republican Party, still reeling from its heavy defeat by Democratic President Barack Obama in the November presidential elections.