The heart of the Senate gun bill will be expanded requirements for federal background checks for gun buyers, the remaining primary proposal pushed by Obama and many Democrats since 20 first-graders and six women were shot to death in December at an elementary school in Newtown, Conn. Senate Democratic leader Harry Reid of Nevada has said there aren't enough votes to approve a ban on assault weapons, while prospects are uncertain for a prohibition on large-capacity ammunition magazines.
Today, the background checks apply only to sales by the nation's roughly 55,000 federally licensed gun dealers. Not covered are private transactions like those at gun shows and online. The Senate measure is still evolving as Sens. Chuck Schumer, D-N.Y., Joe Manchin, D-W.Va., and Mark Kirk, R-Ill., use Congress' two-week recess to negotiate for additional support in both parties.
Expanding background checks to include gun show sales got 84 percent support in an Associated Press-GfK poll earlier this year. Near-universal background checks have received similar or stronger support in other national polls.
Polls in some Southern states have been comparable. March surveys by the Quinnipiac University Polling Institute found more than 9 in 10 people in Florida and Virginia backing expanded background checks, the same margin found by an Elon University Poll in North Carolina in February.
Analysts say people support more background checks because they consider it an extension of the existing system. That doesn't translate to unvarnished support from lawmakers, in part because the small but vocal minorities who oppose broader background checks and other gun restrictions tend to be driven voters that politicians are reluctant to alienate.
"It's probably true that intense, single-issue gun voters have been more likely to turn out than folks who want common-sense gun laws," said Mark Glaze, director of Mayors Against Illegal Guns, the group that Bloomberg helps lead. Glaze, however, said he believes that has changed somewhat since Newtown and other recent mass shootings.