Sarah Palin
The Alaska governor, a surprise pick as John McCain's running mate, generated immediate excitement around his campaign, particularly with the Republican Party's conservative base. Her speech at the Republican National Convention in St. Paul was hailed widely.
Palin has billed herself as a reformer, someone who wasn't afraid to take on her own party's elite in Alaska and is ready to shake up an entrenched establishment in Washington. Others have questioned whether her experience - two years as governor, four years as mayor of a city of less than 10,000 - qualify her to be vice president, "a heartbeat away from the presidency."
She is coming off rough performances in recent interviews with Katie Couric of CBS News, and the debate with Joe Biden is seen as key for her to bounce back and show the American public she is ready for what lies ahead.
Born: Feb. 11, 1964
Birthplace: Sandpoint, Idaho (moved to Alaska as an infant)
Home: Wasilla, Alaska
Family: Husband, Todd; five children
Religion: Protestant
Current job: Governor of Alaska, elected 2006
Employment history: Chairwoman of Alaska Oil and Gas Conservation Commission, 2003-04; mayor of Wasilla, 1996-2002; Wasilla City Council member, 1992-96. Was owner with her husband of a snowmobile, watercraft and all-terrain vehicle business; worked as a sports reporter for two Anchorage, Alaska, television stations
Education: University of Idaho, B.A., 1987
Website: www.johnmccain.com