The Senate's procedural vote Thursday on gun control legislation was historic, marking the first time either chamber has advanced a major firearms bill to the floor since the assault-weapons ban of 1994.
But both sides are girding for an intense debate ahead, as supporters of the legislation face a looming series of procedural hurdles -- on an issue where the politics is more heated than for virtually any other. The National Rifle Association, which is adamantly opposed to the bill in its current form, has already threatened to keep careful score of lawmakers' positions, even on procedural votes.
The pressure from the gun lobby, as well as lingering concerns from lawmakers in states with a tradition of gun rights that the bill could limit them, continue to make final passage a heavy lift.
Sen. Chuck Schumer said it would be a "struggle" to get the necessary votes to advance to final passage.
"The hard work starts now," Senate Majority Leader Harry Reid said after Thursday's procedural vote.
President Obama, while applying more pressure to lawmakers, plans to have the mother of a Newtown shooting victim deliver the weekly White House radio address on Saturday.
The Senate voted 68-31 Thursday to advance to debate on the bill. What follows will be a string of votes on amendments, at least one of which -- on reining in the background checks provision -- is considered vital to winning conservative and moderate support. Sens. Joe Manchin, D-W.Va., and Pat Toomey, R-Pa., offered a compromise measure that would expand background checks to gun-show and Internet sales, while exempting some casual transactions among family members and others. It is meant to assuage concerns that the current version could be a burden on hunters and families exchanging firearms among them.
Republicans could also throw up amendments in the days ahead that would turn off Democrats.
And, importantly, Senate leaders will likely have to marshal another round of 60 votes in order to cut off debate and proceed to final passage. That procedural vote could be more difficult than Thursday's, as Schumer acknowledged.
NRA Institute for Legislative Action Director Chris Cox, in a pointed letter to senators this week, reminded them that the NRA is watching their votes carefully -- on everything from amendments to procedural matters.
"Given the importance of these issues, votes on all anti-gun amendments or proposals will be considered in NRA's future candidate evaluations," Cox wrote. He urged the Senate to replace many of the bill's provisions with language focused on the mental health system, school security and prosecuting violent criminals.
"Rather than focus its efforts on restricting the rights of America's 100 million law-abiding gun owners, there are things Congress can do to fix our broken mental health system; increase prosecutions of violent criminals; and make our schools safer," he wrote.
The NRA has already announced that the Manchin-Toomey proposal on gun checks still does not do enough to protect Second Amendment rights.
Reid is looking to start the votes on amendments -- including the Manchin-Toomey proposal -- early next week. Proponents say expanded background checks, along with proposals to toughen penalties for gun trafficking and boost school security aid, are common-sense measures that could help reduce the likelihood of tragedies like the Newtown school shooting last December.