Right from the start of her political career, Sarah Palin has shown a willingness to take on the powers that be in her home state of Alaska.
Republican Sen. John McCain's surprise pick to be his vice-presidential running mate challenged a three-term incumbent in her very first race for executive office - the 1996 race for mayor of her small hometown of Wasilla, Alaska.
Running as "a new face and new voice" who would clean up city hall while holding the line on taxes, the two-term city councilwoman knocked off the incumbent. It would become a familiar pattern for a politician who bucked the establishment almost every step of the way to become by far the state's most popular politician.
"Sarah Palin for her entire political career has been underestimated," Paulette Simpson of the Alaska Federation of Republican Women told the Associated Press. "She's tough. She's tenacious. I believe she does have what it takes to get out there."
Not well known nationally, the 44-year-old Mrs. Palin is widely credited within the party with rejuvenating and reviving the image and rebuilding the fortunes of the troubled Republican Party in Alaska.
Her 2006 election as governor, in which she dispatched incumbent Gov. Frank Murkowski in the GOP primary and popular former Democratic Gov. Tony Knowles in the general election, made her the state's youngest governor and its first female chief executive.
She calls herself an "Alaska hockey mom." She was a high school basketball star and one-time Miss Alaska contestant. Her blue-collar husband, Todd, works on the North Slope oil fields and belongs to the United Steelworkers of America.
The Anchorage Press described her in a 2006 profile as a "small-town, angel-faced mother of four, an avid hunter and fisher with a killer smile who wears designer glasses and heels, and hair like modern sculpture, who's taking it to the boys ever so softly." The couple's fifth child, a boy named Trig, who has Down syndrome, was born in April.
Born Sarah Louise Heath in February 1964 in Sandpoint, Idaho, she moved to Wasilla, Alaska, about 30 miles from Anchorage, as an infant. Her parents were both in education: her father an elementary school teacher and her mother a school secretary.
Mrs. Palin earned the nickname "Sarah Barracuda" for her hard-charging style as a point guard on the basketball court, a nickname political opponents would revive in later electoral battles.
She studied journalism and political science at the University of Idaho, returning to Alaska to join her husband's commercial fishing business and to do occasional work as a local television sports reporter.
She entered politics in 1992, winning a seat on the Wasilla City Council, and four years later was elected the town's mayor.
She made a failed run for the GOP nomination for lieutenant governor in 2002, but then-Gov. Murkowski appointed her to the state's influential Oil and Gas Conservation Commission.
While rising through the ranks, Mrs. Palin has also shown an ability to break with the state's Republican power barons. While at the energy commission, she clashed with state party Chairman Randy Ruedrich and resigned from the panel after less than a year to protest what she called her colleague's "lack of ethics."
She also broke with then-state Attorney General Gregg Renkes over suspected conflicts of interest. Mr. Renkes and Mr. Ruedrich were both subsequently forced to step down from their posts. She decided to challenge Mr. Murkowski for governor in 2006, running as a party maverick who could clean up the mess in Juneau, the remote state capital.
Her winning campaign painted her as an clean-government outsider willing to take on her own party establishment. As governor, she pushed through a major new ethics bills and - in a move that plays well with Mr. McCain's career-long drive against wasteful government spending - drove the final stake through the infamous Alaskan "bridge to nowhere," a federal earmark project that had become the arch-symbol of wasteful government pork.
A social conservative who lists her religion as Protestant, Mrs. Palin has a strong pro-life record and opposes same-sex marriage.
Mrs. Palin and her husband, who is partly of native Yupik Eskimo ancestry, have five children: sons Track, 19, and Trig, 4 months; and daughters Bristol, 17; Willow, 14; and Piper, 7. Track Palin enlisted in the Army last year and is slated to deploy to Iraq next month.