You guys know that Fienstien and her kind have introduced AWBs almost every year since 2003, before the old ban even expired, and even after worse shootings, it never even made it out of committees.
http://www.denverpost.com/politics-national/2012/12/assault-weapons-ban-what-happened-to-12-attempts-to-reinstate-it/Even senate majority leader, and big time liberal, Harry Reid, has said there will not be an AWB on his watch.
Even a lot of very left leaning people in this country really like guns, including AR15s and AKs and such.
The democrats know it's a losing issue, and it has cost them dearly before, there will be bills introduced, and foaming at the mouth from the usual suspects, it will never make it to the house floor, those who co-sponsored it will be able to say they "did something", the public will move on to more pressing issues, such as economic problems, just like with the dark knight shooting.
Even when the dems had majorities in both houses, and the white house, they couldn't get one passed, and now republicans still control congress. Obama may have nothing to lose, but the dems would like to gain control of the house in 2014, or not lose more seats.
And, finally, let's not forget that the 1st AWB was in fact repealed by congress in 1996.