It seems unlikely this will go anywhere in Congress if introduced and it's likely unconstitutional. But this gives a clue as to how serious liberals are about using Sandy Hook as the gun control tipping point. It reminds me of a line from 1995's "An American President," where Michael Douglas as POTUS delivers this line in a speech:

 You cannot address crime prevention without getting rid of assault weapons and handguns. I consider them a threat to national security, and I will go door to door if I have to, but I'm gonna convince Americans that I'm right, and I'm gonna get the guns

There is something prophetic in Super Liberal Aaron Sorkin's writing of this line. Note "assault weapons and handguns" and going door to door to get them. This is exactly where liberals are in 2012 after Sandy Hook. That which was just a wistful dream when Douglas mouthed it 17 years ago seems in reach to the anti-gun crowd now. They won't let go of this dream easily.