The initiative would legalize and regulate marijuana for recreational use for Californians 21 and older.  It would also allow pot to be taxed.  It's similar to proposition 19 - which voters rejected last year.  Supporters say the goal is to "regulate marijuana like wine."  The state's non-partisan legislative analyst says if the measure passes, it could mean hundreds of millions of dollars in additional tax revenue.  But the LAO says that would depend on how strictly the federal government enforces U.S. law, which bans marijuana.  Opponents say the initiative would make pot more available to young people and hurt low income communities.  Backers have until mid-December to gather more than 500-thousand signatures to put the measure on next November's ballot.