San Francisco Mayor Gavin Newsom Announces for California Governor Race in 2010

San Francisco Mayor Gavin Newsom is no longer flirting with a run for governor of California — he’s officially in.

The 41-year old mayor announced his bid through Twitter, Facebook and YouTube, a sign the mayor intends to make his next-generation appeal a centerpiece of the 2010 campaign.

“I’m a candidate for governor of California because I know we can do better,” Newsom says looking straight into the camera in his YouTube announcement video.

The two-term mayor will tour Facebook’s headquarters later this afternoon. Newsom has already being “followed” on Twitter by nearly 275,000 people as he has been criss-crossing the state for townhall-style meetings in the last few months. His campaign hopes his new media announcement will directly reach a half-million people by the day’s end.

Look for Newsom to have a difficult Democratic Party primary campaign against California Attorney General Jerry Brown (also a former California Governor) and Los Angeles Mayor Antonio Villaraigosa.

This campaign will be costly and brutal.