After the elementary school shooting in December 2012 in Newtown, Conn., President Barack Obama promised to elevate gun violence as a national priority. Vice President Joe Biden led a committee tasked with soliciting ideas from all sides of the debate and bringing recommendations to the president.

Obama introduced his proposals -- a combination of presidential directives, executive orders and law changes that would require congressional action -- on Jan. 16, 2013. Renewing the ban on assault weapons (which are called modern sporting rifles in the industry) was second on his list:

"Congress should restore a ban on military-style assault weapons, and a 10-round limit for magazines,” he said at the White House. "The type of assault rifle used in Aurora, for example, when paired with high-capacity magazines, has one purpose -- to pump out as many bullets as possible, as quickly as possible; to do as much damage, using bullets often designed to inflict maximum damage.”

As Obama indicated, a ban on such weapons is not something he can decree. Congress would have to pass a law. On Jan. 24, Sen. Dianne Feinstein, D-Calif., introduced S. 150, which would upgrade an assault weapons ban that expired in 2004. The bill would ban the future sale, transfer, manufacture and importation of 157 specific kinds of semi-automatic guns and impose the same restrictions on ammunition magazines that contain more than 10 rounds. It would also ban rifles, handguns and shotguns that accept detachable magazines and have certain physical characteristics, including a pistol grip or folding stock.

"The common thread in these shootings is that each gunman uses a semi-automatic assault weapon or a large-capacity ammunition magazine,” Feinstein said in a Capitol Hill press conference, mentioning other recent mass shootings. Her goal, she said, is to "dry up the supply of these weapons over time."

Rep. Carolyn McCarthy, D-N.Y., said she would introduce a companion bill in the House once it is back in session.

Feinstein herself said passing the legislation would be "really an uphill road,” but the bill's introduction moves the needle on Obama's promise. We rate it In the Works.