The remarkable enthusiasm around Barack Obama's election makes the thought of running against him in four years daunting. But potential Republican challengers are already jockeying for that right. The GOP's path back to power is murky and its coalition fractured, but one thing should be crystal clear: Sarah Palin will not be the party's nominee in 2012, or even a serious contender.

Dispirited Republicans cite Palin's rise as one of the few bright spots of the 2008 campaign. Her arrival on the scene undeniably gave John McCain a critical boost, without which the race may well have been over by Labor Day. But there are political, geographic, and personal factors that all but foreclose a near-term political future for her outside Alaska.

First of all, there is her performance as a vice presidential candidate. Palin rejuvenated conservatives in the Republican Party with her cultural stands and antipathy for elites of all sorts, the media in particular. How much life this message has in a GOP that will spend the next two years rethinking its brand is debatable. What's more, there is no shortage of potential candidates who can carry this banner should it retain its appeal, albeit without the gritty panache of Palin.

But for all the enthusiasm she generated among the base, Palin has become a caricature for millions of casual political observers. Many people, including crucial swaths of the independent and youth vote, will be unable to distinguish the real Sarah Palin from Tina Fey's Saturday Night Live impression of her. To them, she will always be remembered, fairly or not, as an overmatched vixen in an overpriced wardrobe.

The fundamental question, then, is: Do Republicans at the grass-roots and national levels really want to start the most significant rebuilding the party has faced since Watergate, having to convince a large segment of voters that Palin is qualified to be president, when a majority of Americans recently said otherwise?

There is also the inconvenient reality that Palin would have to mastermind a run for president at a distance of nearly 4,000 miles and four time zones from New York City and Washington. The Internet makes many things possible, but changing geography is not yet one of them. And who among the savvy D.C. insiders that are essential to building buzz for potential candidates is willing to hop on a snow machine for regularly scheduled huddles in Wasilla?

Since Ronald Reagan's election in 1980, there has not been a presidential nominee whose "day job" kept him more than one time zone from the centers of media and government. George W. Bush had the greatest distance to travel, but his disadvantage was mitigated by three factors, none of which apply to Palin's circumstances. He was the head of a decentralized executive branch in which the lieutenant governor arguably has more day-to-day responsibilities. His father and grandfather had spent decades building the family name and network in Washington, including 12 years in the White House. And this base allowed him to build a sense of inevitability two years out from the presidential race, meaning that advisers and fellow governors were tripping over themselves to come to Austin to meet with him and discuss a run.

Four more years as governor (assuming she wins re-election in 2010) may add some gravitas for Palin, but it will also complicate her path to the nomination. For example, the gas pipeline deal that she brokered will move from the conceptual stage to implementation, bringing on the attendant complexities. And she will face a legislature with Democrats, and some Republicans, eager to take the gleam off her credentials as a reformer.

But perhaps the most difficult roadblock to Palin's candidacy is the same thing that has generated so much of her appeal--her status as America's most famous "hockey mom." Putting aside the demands of being governor, Palin's domestic plate runneth over. She is a mother of five, including an infant with Down syndrome and a son in Iraq. She is also about to become a grandmother to the child of her 17-year-old daughter, with all the responsibilities that entails. And don't forget her remaining daughters, ages 13 and 7.

Finally, her husband's careers in oil production and commercial fishing necessarily mean he is away from home regularly, as does his championship-level snow-machine racing. By all accounts, the Palins have raised a happy family while excelling in their chosen fields. And they appeared to manage their domestic duties seamlessly during the recent campaign. But this was a two-month sprint, not the multiyear marathon required of successful presidential nominees.

Sarah Palin will remain a star in the Republican Party for decades, perhaps even ascending to the presidency someday. But to imagine that day is just four years away is to deny the very simple calculus of her current situation.