but I don't think they're looking at November. I think they're anticipating the Presidents re-election and looking past November to the 2014 mid-term.
I didnt vote for Obama in 08, and I won't vote for him this November. Back in 07-08 when the MJ constituency of voters were pushing "Obama gonna legalize it", I was the person pushing back "you're an idiot if you believe he's going anywhere near that issue if he gets elected - not in his first term anyway". I believed that then and to my surprise most of his MJ constituents would agree with that statement back then. Whether they still believe that way or not is anybody's guess. Perhaps adding pro-mj language to the national platform the DNC is hoping those folks will view it as a signal. Personally I think he would like to be the President remembered for putting an end to that decades old racist policy, and if it becomes an issue in the 2014 midterm election he may well be - IF he's re-elected. If he's not re-elected, Democrats will at least have an issue card to play to independent voters (and right leaning libertarians) in tight races.
Don't forget Democrats are classic populists. They change positions with the political winds. Right now on the political weather map libertarians are a pretty strong breeze that is trending toward the right.
Dems have never been ones to do nothing while support grows to the right. Think about it, they transformed their image from the party of slavery and the KKK, into the party of equal rights and social justice in less than a century - and in that time, with some degree of success, managed to paint the Grand Old abolitionist Party in the image of greedy misogynistic old white men and tea-bagging rednecks. Never underestimate how quickly populists can turn "180 degree U-Turn" on a dime.
They know what all of us here at DP know and what the GOP is blind to - libertarians are not [yet] strong enough in numbers to win outright, but are now at that 9 or 10% (double-digit) level that is not small but small enough to organize, and plenty big enough to tilt elections. We've already seen the right trying to pander to us with libertarian language on the economy and fiscal issues (ie Newt's position on the Fed,etc.). I would not be a bit surprised if the Democrats start doing the same to try and appeal to social libertarians.