But Palin's clean-hands reputation has recently come into question. A legislative panel is investigating whether she dismissed Alaska's public safety commissioner because he would not fire her former brother-in-law as a state trooper. Trooper Mike Wooten went through a messy divorce from Palin's sister.

The governor denied orchestrating the dozens of telephone calls made by her husband and members of her administration to Wooten's bosses. She says she welcomes the investigation: "Hold me accountable."

Even before McCain picked her, people outside Alaska were beginning to notice the young governor with the bright smile — runner-up in the 1984 Miss Alaska contest — whose good looks spawned a bumper sticker that read: "Coldest State. Hottest Governor." Last December, she posed for the fashion magazine Vogue but turned down their effort to put her in runway attire.

"At first they had me in a bunch of furs," she said of the photo shoot. "Yeah, I have furs on my wall, but I don't wear furs. I had to show them my bunny boots and my North Face clothing."

She did the photo shoot while a few months pregnant, which Vogue and the public did not know.

What she knew and others didn't at the time was that her son, Trig, would be born with Down syndrome. There was never a doubt that she and Todd would have the child, she told the AP earlier this year in describing what she and her husband have confronted.

"We've both been very vocal about being pro-life," Palin said. "We understand that every innocent life has wonderful potential."

Still, Palin waited a few days before telling her husband, who was out of town. Once Todd returned and heard the prognosis, he told his wife: "We shouldn't be asking, 'Why us?' We should be saying, 'Well, why not us?"'

Trig Paxson Van Palin (an homage to the rock band Van Halen) was born in April. With Trig in tow, Palin returned to work a few days later, for a meeting of her energy team.

Her handling of this experience, her opposition to abortion, even her leadership of her high school chapter of the Fellowship of Christian Athletes all could help McCain's standing with social conservatives who have been skeptical of him.

Palin is "a woman of faith who has a strong position on life, a consistent opinion on judges," said Mathew Staver, dean of Liberty University School of Law and founder of the legal group Liberty Counsel, who has sought to coalesce evangelicals around McCain. "This will absolutely energize McCain's campaign and energize conservatives."

Alaska's first female governor arrived at the Capitol in 2006 on an ethics reform platform after defeating two former governors in the primary and general elections.