Senate moves to begin debate on gun measures WASHINGTON -- The Senate may begin voting as soon as Thursday on legislation intended to reduce gun violence, after Senate Majority Leader Harry Reid (D-Nev.) decided Tuesday to initiate the procedural steps required to overcome a threatened filibuster by a group of Republicans. Democrats were closing in on the 60 votes they would need to thwart an attempt to block the Senate from considering a package of gun legislation, which includes measures that were crafted in the wake of December's Sandy Hook Elementary school shooting, which left 26 dead. "It would be a real slap in the face to the American people not to do something on background checks, on school safety, on federal trafficking, which everybody thinks is a good idea," he said. Among Republicans, a divide has emerged between those who are vowing to prevent the Senate from considering proposals that they view as a threat to 2nd Amendment rights, and those who are open to voting on the contentious issue on the Senate floor. On the first full day of business after a two-week-long spring recess, gun-control proponents appeared close to having the votes needed to defeat a filibuster, but were not assured of that. Several Democrats who represent Republican-leaning states and face challenging reelection fights in 2014 said they were not yet prepared to support bringing the issue to the floor. Sen. Joe Manchin (D-W.Va.), who has emerged as the key figure in crafting a proposal to expand background checks for most gun purchases, said he was continuing to work with Republicans on a version that would attract sufficient GOP support to pass. Background checks are considered the centerpiece of the gun legislation the Senate would consider. Manchin, after briefing his Democratic colleagues on the status of talks, said he promised his party's leaders a status report Tuesday evening. "We're still working," Manchin told reporters. Everyone's working in good faith, and hopefully we'll have something very good. Sen. Pat Toomey (R-Pa.) has emerged as Manchin's primary Republican negotiating partner after months-long talks with Sen. Tom Coburn (R-Okla.) hit a stalemate. Sen. Susan Collins (R-Maine), who has co-sponsored other gun proposals that will be part of the larger bill, said she has also spoken with Manchin in recent days and is "very encouraged" with the legislation he's crafting. Asked if he could get to 60 votes to proceed to a debate on the bill if Manchin cannot work out a compromise approach to background checks, Reid told reporters: "I don't know." Also Tuesday, family members of some of the 26 victims of the Newtown, Conn., school shooting arrived on Capitol Hill to begin a senator-by-senator lobbying effort in favor of stricter gun rules. The group, which also met with Vice President Joe Biden for breakfast, began by huddling with Connecticut's Democratic senators, Richard Blumenthal and Chris Murphy. If the Congress of the United States listens to its conscience and to its constituents, it will pass gun-safety measures this week. Blumenthal said the group was "aghast" at the notion that a minority of Republicans could block legislation from reaching the Senate floor. "They expected to be here in Washington arguing for the right vote, not arguing for a vote to happen at all," Murphy added. So we spent a lot of the meeting just trying to explain to them the process. Opposition remained among other Republicans, however. Sen. Ted Cruz of Texas maintained that senators were already debating the merits of new gun laws, downplaying the impact of the filibuster effort he is helping to lead. "I would be happy to spend the next two or three weeks every day on the floor of the Senate with us debating this issue, asking what legislation would actually prevent violent crimes, and how would this legislation impact the 2nd Amendment rights of all citizens," he said. Sen. Mike Johanns of Nebraska said the Newtown massacre "as tragic as tragic is," but that he continues to oppose the gun legislation being considered. "This has been a political response to a very tragic situation," he said. You can pass this bill. Newtown still would have happened. twitter.com/@mikememoli