UPDATE: Commenter makes a good catch picking up typos in the headline. We regret the error.

Sen. Dianne Feinstein, the Democratic former mayor of San Francisco, will co-chair the campaign to defeat Proposition 19, the marijuana legalization initiative on the ballot in November, according to a press release today.

Her co-chair will be L.A. County Sheriff Lee Baca. This is a huge win for the opposition. Feinstein's already voiced opposition, but she seems to be really putting some force behind it with this move.

“California will not see a single positive result if Proposition 19 passes,” said Senator Feinstein. “It is a poorly constructed initiative that will cause harm to Californians on our roadways, and in our schools, workplaces and communities. I look forward to working with Sheriff Baca to ensure we defeat Proposition 19 in November.”

(Proponents believe prohibition of marijuana impinges on the rights of Californians to do as they please with a substance no more harmful than alcohol or tobacco, wastes precious law enforcement resources, and leads to racial-profiling.)

Regardless, Feinstein represents probably the key constituency supporters will need for Prop. 19 to pass: moderate Democrats who haven't smoke weed since college and are largely persuadable on this issue either way.

The partisans on the issue are already in their respective camps. The “pro” side now has two challenges: Get their staunch partisans, who probably aren't very reliable voters, to come out. And, persuade moderates, make them feel comfortable with legalization. Feinstein just made that second task harder.

LA Weekly