In 1998, she had been elected Attorney General of Arizona, after having served as United States Attorney for the District of Arizona. She won the gubernatorial election of 2002 with 47% of the vote, defeating her republican opponent, former congressman Matt Salmon who had received 44% of the vote.
Napolitano was born in New York City and raised in Pittsburgh and Albuquerque, New Mexico. She graduated from Santa Clara University in California and University of Virginia law school.