Now, 44-year-old Sarah Palin, a mother of five who gave birth to her last child in April, could be a heartbeat away from the presidency, should her 72-year-old running mate win in November.

Not since George H. W. Bush picked Dan Quayle, an obscure senator from Indiana, as his vice-presidential choice

20 years ago has a running mate been greeted with such a collective, "Who?"

"She's not from these parts, and she's not from Washington," is how Sen. John McCain, the presumptive Republican presidential nominee, described Palin as he introduced her yesterday in Dayton.

"She stands up for what's right and she doesn't let anyone tell her to sit down," McCain said.

The former Sarah Louise Heath is the third of four children born to Chuck and Sally Heath: Chuck a teacher, Sally a secretary.

There's a storybook quality to Sarah Palin's life, a blue-collar tale of pluck, good fortune and independence.

Palin has been held up by many evangelicals as a model for her decision to give birth to her fifth child in April after learning that he has Down syndrome.

"I think that's a plus in her favor with conservatives," said the Rev. Don Argue, a past president of the National Association of Evangelicals and chancellor of Northwest University in Seattle.

Palin has ties to the Assemblies of God, one of the largest Pentecostal denominations in the country. Her selection was welcomed by evangelicals who previously had questioned McCain's commitment to their values.

"Sen. McCain's selection of Alaska Gov. Sarah Palin is an outstanding choice that should be extremely reassuring to the conservative base of his party," Focus on the Family Action founder James Dobson said. He called her refusal to abort her fifth child "bravery and integrity in action."

Richard Land, president of the Southern Baptist Ethics & Religious Liberty Commission, said Palin resonates with evangelicals: "She's one of us."

Palin grew up in Wasilla, a town of 9,800 near Anchorage, and was a point guard on her state-champion high-school basketball team and a leader of the Fellowship of Christian Athletes.

After earning a degree in journalism from the University of Idaho, she eloped with her high-school sweetheart, Todd Palin, a commercial fisherman, North Slope oil-field worker and state champion in long-distance snowmobile racing.

Palin launched her political career in 1992, presenting herself as a "new face, new voice" on the Wasilla City Council. Four years later, at 32, she was elected mayor.

Palin has skillfully navigated her way through the rough and often corrupt Alaskan political thicket, striking an effective balance between self-promotion and challenging the Republican powers-that-be.

In her speech yesterday in Dayton, Palin came across as forceful, a trait that originally attracted her to the chieftains of Alaska's Republican Party, who arranged for her to be appointed to the Alaska Oil and Gas Conservation Commission in 2003.

Shortly after joining the commission, Palin led an ethics probe of the commission's chairman, Randy Ruedrich, also the state GOP chairman. Facing conflict-of-interest allegations, Ruedrich admitted ethics violations and resigned.

Palin also joined an ethics investigation against Alaska's Republican attorney general, who had close ties to then-Republican Gov. Frank Murkowski. Suddenly, she was an outsider in her own party. But that paid off with corruption-weary Alaska voters, who liked her independence.

"She has very, very good political instincts," said Mike Kenny, former Alaska Teamsters union president and now a Democratic candidate for the state House of Representatives. Kenny, as Teamster president, endorsed Palin in the 2006 gubernatorial primary, but does not call himself a supporter now.

"I think she's a mile wide and about an inch deep," he said. "But she has the Alaskan touch -- she's a hockey mom, she hunts, she fishes. Her husband is a man's man, her son joined the Army ... These are powerful images that resonate with a lot of people."

Marc Hellenthal, a pollster in Anchorage, said Alaskans like Palin because she has a reputation for "speaking her own mind and then worrying about whether it's popular afterward."

One potential blemish on Palin's record is an investigation into charges that she pushed early this year for the firing of an Alaska state trooper -- her ex-brother-in-law -- who was involved in a bitter child-custody dispute with Palin's sister.

There's no evidence yet that the charge has seriously damaged her. In the week before the Democratic convention, Hellenthal said, Palin's approval ratings were 79 percent, the highest of any Alaska politician in history.

Few anticipated the former small-town mayor becoming governor two years ago. And no one saw yesterday's announcement coming.

"Everybody's still in a state of shock," Hellenthal said.

Information from the Religion News Service was included in this story.