Newsom tossing his hat into the field of Democratic contenders came as no big surprise since it was widely anticipated among political observers that the high-profile mayor would run for the office that will be vacated by Gov. Arnold Schwarzenegger, who is barred from running again due to term limits.
Whoever wins next year will have their hands full. California is wrestling not only with the recession but also a long-running drought and a sharply partisan legislature.
"We've gotten things done in San Francisco by putting politics aside and focusing on finding solutions to tough problems," Newsom said in a written announcement. "State government is failing because the politicians in Sacramento spend all their time fighting each other instead of fighting for Californians."
Newsom sent the announcement, along with a request for contributions, to 450,000 potential supporters via e-mail, Twitter and Facebook.
Insurance Commissioner Steve Poisner, who is running for the Republican nomination, said in a statement that he welcomed Newsom to the race and looked forward to debating him because "style and rhetoric will only take California so far."