Newsom graduated from Redwood High School in Larkspur, California, in 1985, and in 1989 from Santa Clara University with a Bachelor of Arts degree in political science. His PlumpJack Wine Shop, founded in 1992, grew into a multimillion-dollar enterprise, and now includes bars, restaurants, and a Lake Tahoe hotel called Squaw Valley Inn. He was first appointed by Willie Brown to serve on San Francisco's Parking and Traffic Commission in 1996, and was appointed the following year as Supervisor. Newsom drew voter attention with his Care Not Cash program, designed to move homeless people into city assisted care. He defeated the Green Party's Matt Gonzalez 53% to 47% in a run-off in his race for mayor in 2003, becoming the youngest mayor of San Francisco since John W. Geary.
In March 2010, he announced his candidacy for Lieutenant Governor, setting off speculation about possible successors if he were to win. In June 2010, he received the Democratic nomination for Lieutenant Governor. Newsom won the 2010 lieutenant governor election on November 2, 2010.