(CBS NEWS) After months of lobbying, negotiating, and deal-making, the Senate Wednesday moved forward with a critical piece of the Obama administration's gun safety proposals, a modest victory for gun control advocates but just one small step toward enacting legislation that would more strictly regulate gun ownership in America.
The Senate voted to begin debate on a bill that would significantly expand background checks for gun sales, which has long been a top priority for gun control advocates.
Easily surpassing the 60-vote threshold with the support of several Republicans, Senate Majority Leader Harry Reid, D-Nev., was able to avert a Republican-led filibuster attempt that aimed to block a full Senate vote of the bill. The legislation is expected to eventually garner the 50-vote majority needed to pass, though the timing of a final vote is unclear.
Republicans opposing the bill are prepared to invoke a rule to force the Senate to wait 30 hours before amendments could be considered. On top of that, Reid said that he expects dozens of amendments to be considered, including several GOP proposals that are doomed to fail but will effectively slow down the process.
"Some of them are going to take a little bit of time," Reid said Wednesday. "We're not going to finish the bill this week. I don't know if we'll finish it next week."
The legislation, though modest in its legislative mandate, is the product of a hard-fought campaign to override the vocal group of Republicans pledging to block any legislation that would at all strengthen regulations on gun ownership. In recent days, the president and vice president have pushed for the bill through personal phone calls to lawmakers and public speeches, while First Lady Michelle Obama delivered an emotional address about gun control in Chicago. Meanwhile, the families of slain Newtown victims have been engaged in a door-knocking campaign in the halls of the Capitol, personally urging members to pass laws that they say would have protected their loved ones.
Wednesday marked a major turning point for the bill's prospects, when Republican Sen. Pat Toomey, R-Pa., announced his support for a version of the bill that would include an amendment he co-sponsored with Sen. Joe Manchin, D-W.Va., a pro-gun Democrat, and which aimed to make the bill more palatable to Republicans.
That compromise, according to Manchin and Toomey, would close the so-called "gun show loophole" and mandate a background check for online gun sales. But it also provides exceptions to the requirement when a gun is transferred as a gift between family members or close friends.
Reid has said he will take this amendment up first, and it is expected to pass without major disruption.
Even so, Sen. Minority Leader Mitch McConnell, R-Ky., reaffirmed Thursday morning his decision to vote against cloture on the gun bill, citing as his opposition the provisions that will be stripped pending the Manchin-Toomey amendment passes.
Pending the final Senate vote, the gun legislation will move to the House, where its fate is yet more uncertain: In the GOP-dominated and sometimes unpredictable chamber, any gun legislation faces an uphill battle. But Toomey said Wednesday that he sees "substantial numbers of House Republicans that are supportive of this general approach."
"Of course they want to look at the specifics of the legislation," he said, "but there are definitely Republicans in the House who support this."
Lucy Madison, CBS NEWS