KEY POINTS:
As a British newspaper put it, her rise from small-town girl to global icon demonstrates "the endless possibilities of the American Dream".
She's a source of widespread fascination, an inspiration to those whose horizons mightn't otherwise extend beyond the outskirts of their insular communities, a reminder that ordinary people can achieve extraordinary things.
She is, of course, Britney Spears, the pop princess who this week completed an amazing comeback from the brink of self-destruction by getting through a brief public appearance without making a spectacle of herself.
Some even described it as a "resurrection," although comparing her largely self-inflicted woes with the crucifixion seems a bit of a stretch.
Sarah Palin's narrative is less dramatic, being (thus far at least) all rise and no fall, but in the blink of an eye she has joined Britney in the vanguard of celebrity culture.
Perhaps the greatest irony of this irony-rich election campaign is that within weeks of the Republicans portraying Barack Obama as a political Britney Spears, a glamorous but vacuous star, they themselves are running on celebrity power.
It's Palin, not Obama, who's the Britney in this race, the candidate who's famous for being famous, the empty vessel who can be reconfigured to suit the vagaries of the market/electorate and the commercial/political imperatives of her backers.
A distinguishing feature of celebrity culture is the discrepancy between fame and achievement. Formerly mayor of a large village, Palin has been governor of a sparsely populated backwater since late 2006.
Her launch-pad was her speech at the Republican Convention, a standard hatchet job delivered with gusto but devoid of substance.
A political speech like many others then, so why the gushing praise? Because another distinguishing feature of celebrity culture is the compulsion to invest everything the star does with significance and distinction, even when it's banal or mediocre.
Nothing bears this out better than the life and work of Andy Warhol, a seminal figure in both pop and celebrity culture. In 2006 one of Warhol's Campbell's Soup can paintings fetched $17.6 million.
Palin's boosters will go to extraordinary lengths to inflate her modest CV.
Take this from the Daily Telegraph: "The first myth is that she is a political neophyte who has come from nowhere. In fact, she and her husband have for decades run a company in the highly political commercial fishing industry, where holding onto a licence requires considerable nous and skill."
Well, if she can wrap Alaskan fisheries officials around her little finger, dealing with Putin and Ahmadinejad should be a doddle. And if you're confused by that reference to decades, I can confirm that Palin is only 44.
Obama hardly has a bulging resume either but at least he got where he is today the hard way - by overcoming a heavyweight opponent in the most ferociously contested primary series in recent history.
Palin was shoulder-tapped by John McCain and even then by default, after his first and second choices were vetoed for being unsound on abortion.
Celebrity makes its own rules. In the Lewinsky affair Bill Clinton, who disconcertingly morphed from President to celebrity as the mood took him, was held to lower standards of behaviour and accountability than most middle managers.
Palin has been elevated to the forefront of national - and potentially international - affairs with a haste and lack of scrutiny that no decent-sized government department or company would contemplate.
She also benefits from the tendency to discount celebrities' eccentricities or downright nuttiness on the basis that it goes with the territory. Thus Madonna's star is undimmed by her enthusiastic membership of a cult that ascribes protective powers to a piece of red string worn around the wrist.
For her part Palin believes that life commenced 5000 years ago when God created the world in six days and cleaned his fingernails on the seventh.
Insofar as one can be bothered responding to wilful ignorance, it's worth pointing out that to hold this belief requires the dismissal of a mountain of hard evidence and the rejection of the principle that rational inquiry leads to objective knowledge which has underpinned Western civilisation since the Enlightenment.
She also believes that America is doing God's work in Iraq, which makes her as militantly monotheistic as Richard the Lionheart and Osama bin Laden.
Celebrity is make-believe. And as Bruce Springsteen reminds us in his bleakly allegorical song Magic, illusionists depend on a supply of eager dupes: "I got a shiny saw blade/All I need's a volunteer/I'll cut you in half/While you're smiling ear to ear."
