Sarah Palin, a former runner-up in the Miss Alaska beauty contest, burst on to the political scene in 2006 by becoming both the first female and youngest governor in Alaskan history at the age of 42.
She had previously gained statewide attention as a gutsy maverick unafraid to speak truth after whistleblowing on ethical violations by state Republican Party leaders during her time on the Alaska Oil and Gas Conservation Commission.
A "soccer-mom" type with telegenic appeal, Mrs Palin is a real life Miss Congeniality — she won the title in the Wasilla beauty pageant back in 1984.
But the mother-of-five combines her homely air with a keen grasp of the issues and a formidable campaigning style.
A strong social conservative and a staunch supporter of gun rights, she is hugely popular in Alaska — a poll published last month showed her approval rating at 80 per cent.
Mrs Palin is strongly pro-life — typified, observers say, by the fact that her fifth child, born in April, has Down's Syndrome. The Palins also have teenage son, Track, and three young daughters, Bristol, Willow, and Piper.
She also opposes same-sex marriage, but has often sympathised with the concerns of gay community about discrimination and has implemented legislation ensuring equal benefits for same-sex couples.
After running her gubernatorial campaign on clean government, Mrs Palin has successfully pushed through an ethics Bill as well as shelving pork-barrel projects supported by fellow Republicans. She is a spending hawk, having slashed the state's construction budget by $237 million - the largest cuts in Alaskan history.
After taking office, she followed through on a campaign promise to sell a Windward II jet purchased on state credit. Placing it on eBay three times, she eventually sold it to the highest bidder for $2.7 million.
Mrs Palin's energy stance dovetails nicely with that of Mr McCain — promoting resource development while also taking steps to address climate change and environmental issues. She has recently announced plans to create a new sub-cabinet group of advisers, tasked with reducing greenhouse gas emissions within Alaska.
However, Mrs Palin is not entirely free of scandal. She is currently under investigation by the state legislature for possible abuse of power surrounding the dismissal of the commissioner for public safety, Walter Moneghan. Mr Moneghan alleges that he was fired because he was reluctant to sack a state trooper who was involved in a bitter divorce and custody battle with her sister, Molly McCann. The governor is said to be co-operating with the investigation, which is being overseen by Democratic State Senator Hollis French.
An Alaskan through and through, Mrs Palin grew up with a love of traditional outdoor pursuits. As a child she regularly got up before dawn to go moose-hunting with her father and is still a strong believer in gun ownership. She is a lifetime member of the National Rifle Association.
Before entering politics she had a number of unconventional jobs including sports reporter and commercial fisherman, the latter alongside her husband Ted, who is a Yupik Innuit.