The most salient point for Democrats to consider about John McCain's new veep, Sarah Palin, is that her looks are deceiving. She is fiercely partisan, charming and politically ice-cold and calculating.

Exuding what the Anchorage Daily News, in a 2006 profile, called an "almost Clintonlike" warmth, former beauty queen Palin has consciously positioned herself as a reformer by leaving a trail of political foes — and friends — who she has broken and used as stepping stones.

But her political opponents say there was another side to the charming candidate -- one captured by her nickname from those basketball years, "Sarah Barracuda." Supporters consider the name a testament to her aggressive play and ferocious defense. But opponents said the name captured a predatory instinct that Palin could turn on friend as well as foe -- one they said occasionally revealed itself in the mayoral years to come.

Palin's meteoric political career has risen less on being ruthlessly reformist and more on being ruthlessly ambitious. How else to explain her presumption in accepting McCain's offer? She is not above using any advantage for political gain, from unabashedly displaying her feminine charms to oddly inserting pro-life rhetoric into her mayoral campaign, from championing regressive sales taxes in place of property and business taxes to sacrificing the careers of even her political allies and sponsors.

If you read one introduction to Sarah Palin, read the article by Alaska's largest newspaper I link to above. She will campaign fiercely, hit hard with her campaign-supplied talking points and be a moving target in the McCain-Palin tag team against the Democrats. Her family (particularly her child with Down's Syndrome) will give her a degree of immunity to harsh personal attacks. She may even use her child as McCain uses his ex-POW status, as a catch-all emblem of her concern for health care and anti-abortion policies.

Yet she brings with her many Achilles heels.

McCain's campaign has already begun positioning Palin to peel off angry Clinton supporters and gender-centric women. But because the campaign has tried this wedge so often and so hamfistedly, it is vulnerable to charges of pimping Palin like a three-dollar whore. In the end, her gender is a net negative for McCain, who will be seen as cynically engaging a political trophy wife with no real qualifications and no expectation that she will ever wield any real power.

Palin's most prominent weakness lies as much in casting doubt on McCain's choice of her as in her own limited experience and zero credentials for being a moment's notice from assuming the duties of commander-in-chief. Biden will be most effective in drawing the distinctions between Obama's perceived foreign policy weakness and her actual weakness. Furthermore, the issue represents a net loss for McCain by trying to have it both ways and undercutting his own best argument.

But Palin's strongest selling point — her reformist reputation — may ultimately work against the GOP ticket more than anything else. Although her reformist image has led her to an 80 percent approval rating in Alaska, there is more to be explored below the permafrost of this narrative. Her method of "reforming" local taxes in Wasilla has hurt lower- and middle-class citizens through regressive local taxes. Her coziness to oil interests, particularly BP, exhibits itself in support for expensive pipelines and drilling in ANWR. Her tactics, far from being brave, included resigning in protest from a board she later criticized and, as noted above, leaving political corpses in her wake.

What she has done to so many even in her own party may yet prove sauce for the goose. And a scandal of any notable seriousness, particularly an abuse of power for personal or professional gain, would have devastating effect on any claim to being a reformer.