Less than a week ago, Sarah Palin was a little-known rookie governor of a remote state, a working mother of five with an infant son, a woman whose life has been forged in the splendor and isolation of the Alaskan wild. Tonight, as she takes center stage at the Republican National Convention in St. Paul, Arizona Sen. John McCain's running mate is a world removed from that life and facing what's likely to be her biggest challenge ever: To introduce herself to a national audience still assessing who she is and what she believes. Her campaign acknowledges that her speech is a crucial moment as she tries to gain control of the debate churning around her. "I think it's a unique opportunity, given the swirl," McCain campaign manager Rick Davis said Tuesday. "It's a chance for her to get out and tell her own story, and to get beyond some of the media fog of the past few days." Conscious of the stakes, Palin has been sequestered this week in her Minneapolis Hilton hotel suite working out the words that will form the public's first impressions of her as the Republicans' answer to the Democrats' mantra of change. Palin suddenly finds herself with a lot of explaining to do. The 44-year-old self-described hockey mom and heroine to social conservatives has reignited a debate about working mothers, not least by being forced to reveal that her unmarried 17-year-old daughter Bristol is five months pregnant. "This is uncharted territory," said University of Minnesota political scientist Kathryn Pearson, a scholar of women in politics. Palin faces other questions as well. An anti-corruption crusader, she's being investigated in Alaska. Legislators there are examining allegations that Palin tried to have her ex-brother-in-law fired from the State Patrol. The McCain campaign has used the revelation of her daughter's pregnancy to burnish the Palin family's credentials on opposing abortion, emphasizing the girl's decision to keep the baby and marry the father.

But that message of personal responsibility might be harder to control amid the teenage flotsam on the Internet, including a MySpace page purportedly belonging to the young father and high school hockey star, identified as Levi Johnston, calling himself a "[expletive] redneck." News reports from Alaska Tuesday indicated Johnston is heading to St. Paul to join the Palin family. His appearance could provide the convention a tabloid element McCain could do without. In preparation for Palin's speech, the McCain camp released a video highlighting the week's most favorable reviews of Palin. That was followed by a prime-time speech by former Sen. Fred Thompson of Tennessee, forcefully rebutting criticism against her. "She is from a small town, with small-town values, but that's not good enough for those folks who are attacking her and her family," said the former "Law & Order" star. "Some Washington pundits and media big shots are in a frenzy over the selection of a woman who has actually governed rather than just talked a good game on the Sunday talk shows," he said. Then, adding a folksy touch, he added, "I can say without fear of contradiction that she is the only nominee in the history of either party who knows how to properly field dress a moose ... with the possible exception of Teddy Roosevelt." Sexism over experience? While some pundits said that Palin had not been thoroughly vetted, McCain supporters have been reveling in what he promised would be an unconventional pick. Like McCain, Palin is often described as an outsider who shook up the GOP in her ascent. One of her first acts as governor was to use eBay to sell the lavish jet plane of her predecessor, fellow Republican Frank Murkowski. During her first legislative session, she pushed an overhaul of the state's ethics laws and a competitive process to construct a gas pipeline. A hunter, snowmobiler, and a lifetime member of the National Rifle Association, Palin has 80 percent approval ratings in Alaska.

But her pre-gubernatorial biography consists mainly of her two terms as City Council member and two terms as mayor of Wasilla (population 9,200), a suburb of Anchorage. There she was able to take credit for cutting property taxes, an act made possible by the area's rapid growth and rise in sales taxes. As governor, she has vetoed millions of dollars in state capital projects, though Alaska, sitting atop a multibillion-dollar fund from its North Slope oil royalties, faces few of the fiscal problems of other states. Many Republicans also smell a whiff of sexism in questions about Palin's scant experience in national politics. "The facts are that Sarah Palin has made more executive decisions as a mayor and governor than Barack Obama has made in his life," said Republican National Committee Victory 2008 chairwoman Carly Fiorina. "Because of Hillary Clinton's historic run for the presidency and the treatment she received, American women are more highly tuned than ever to recognize and decry sexism in all its forms. They will not tolerate sexist treatment of Governor Palin." Full-throttle attacks Pearson, the U of M professor, said Palin's quest for higher office with a Down syndrome baby raises the issue of traditional family values and how women should balance family and work. Even less clear is how Palin with play with swing voters. "Moving from Hillary Clinton to Sarah Palin is a big jump ideologically," said Carleton College political scientist Steven Schier. Meanwhile, the Democrats put out a steady of unflattering revelations Tuesday. Among them: Palin had employed a lobbying firm to secure almost $27 million in federal earmarks as mayor of Wasilla, which does not fit with McCain's image as a pork-buster. While some Republicans have watched the vetting process unfold with some trepidation, her core conservative backers remain enthusiastic. "There are no scandals here," said U.S. Rep. Michele Bachmann, a Minnesota Republican who dined with Palin on a recent tour of the Arctic National Wildlife Refuge, where both support expanded oil and gas drilling. "People say it was a gutsy move on McCain's part, and I agree with that."