WASHINGTON -- It was in front of an enormous painting by an artist from Ohio that a Republican from Pennsylvania and a Democrat from West Virginia shared perhaps the most important handshake of the year Wednesday.
There, overlooking William Powell's fabled "Battle of Lake Erie" in the U.S. Capitol, Sens. Pat Toomey and Joe Manchin set off a different kind of battle, one whose echoes will carry far beyond Washington.
Their bipartisan amendment on a gun control bill already has attracted fire from the right, with Mr. Toomey, the Pennsylvania Republican, immediately being characterized as a traitor for departing from the core conservative belief in nearly unfettered gun rights.
Oliver Hazard Perry, the commander depicted in the painting, swiftly overtook the Brig Niagara as bullets rained on his rowboat, but with several Republicans threatening to filibuster, the battle in Washington could be more protracted.
With pressure building on both sides, the question remains whether Mr. Toomey will emerge as a hero or renegade, departing this legislative battle much like the forlorn figure floating away in the painting.
At the crux of the amendment is a requirement for sellers to conduct background checks whether they do business in firearms stores, at gun shows or over the Internet. Noncommercial transactions -- such as between friends, neighbors or relatives -- would remain exempt.
The proposal includes something for Second Amendment advocates, too. For example, it would allow active military -- who now are only permitted to buy guns where they are stationed -- to also purchase them in their home states.
The proposal does not include Democrat-supported measures to require background checks even for private gun purchases, to outlaw high-capacity magazines and to reinstitute an expired ban on assault weapons.
Still, the Manchin-Toomey plan is widely viewed as the Senate's best chance for advancing gun control legislation.
The proposal doesn't go as far as President Barack Obama wants, but he said Wednesday that it's a good start.
"The agreement does represent welcome and significant bipartisan progress. It recognizes that there are good people on both sides of this issue, and we don't have to agree on everything to know we've got to do something to stem the tide of gun violence," the president said in a statement Wednesday afternoon.
Senate Majority Leader Harry Reid, D-Nev., has assured Mr. Toomey and Mr. Manchin that he will allow a vote on their amendment. First, though, the underlying bill needs to clear a procedural hurdle today. Sixty votes are required to overcome a filibuster.
Mr. Toomey said Wednesday that he hopes there are enough votes but that he wasn't sure.
A number of other Republicans have competing amendments that would increase penalties for gun trafficking, provide more money for school safety programs and strengthen requirements for reporting mental health problems.
Democrats including Mr. Obama, meanwhile, want to go much further by requiring background checks for all transfers of gun ownership, restricting magazine capacity and banning assault rifles.
Mr. Toomey, who normally expends his political capital on fiscal issues rather than culture wars, said he was compelled to intervene. He said the December shooting at Sandy Hook Elementary School in Newtown, Conn., made it obvious that Congress had to do something, and he didn't want legislation to go too far. The Sandy Hook massacre left 20 first-graders and six educators dead.
"There are a number of gun proposals that I think would infringe on Second Amendment rights," Mr. Toomey said.
His own proposal doesn't, he said.
"Candidly, I don't consider criminal background checks to be gun control. I think it's common sense. If you pass a criminal background check, you get to buy a gun," Mr. Toomey said.
The Manchin-Toomey amendment also includes provisions to create a gun-violence task force and to withhold federal grants from states that don't comply with background check requirements.
The latter appears to be in response to pre-emptive legislation introduced in Pennsylvania and several other states to prohibit enforcement of any new gun control measures.
Mr. Toomey and Mr. Manchin both are gun owners with top ratings from the National Rifle Association, which already has blasted their plan as an unnecessary infringement on the right to bear arms.
In a statement Wednesday, NRA leaders said the background checks would not have prevented the Newtown massacre because shooter Adam Lanza used a gun his mother had legally purchased.
"Expanding background checks at gun shows will not prevent the next shooting, will not solve violent crime and will not keep our kids safe in schools," the NRA said in a statement Wednesday. "We have a broken mental health system that is not going to be fixed with more background checks at gun shows."
Other opponents expressed concerns that the measure is the start of a slippery slope that could result in other restrictions on gun ownership. Sen. Ted Cruz, R-Texas, for example, worries that the expansion of gun checks could lead to the creation of a federal registry of gun owners.
Mr. Toomey said he isn't concerned about backlash from conservatives.
"What matters to me is, I think this is the right thing, and I think most Pennsylvanians will agree," he said.
A recent survey by Franklin & Marshall College showed that 94 percent of Pennsylvanians favor increased background checks, so Mr. Toomey isn't risking much by advancing his amendment, pollster G. Terry Madonna said. Rather, Mr. Toomey stands to gain a lot, Mr. Madonna said.
Meanwhile on Wednesday, Mayors Against Illegal Guns abruptly stopped airing television commercials targeting Mr. Toomey for lack of action on gun issues,
and instead issued praise for the senator.
"It takes political courage to sit down at the table and hammer out a compromise on sensible legislation," said Lancaster, Pa., Mayor Rick Gray, a Democrat among 900 city leaders in the advocacy group created in 2006.
In Washington, Pennsylvania Democratic Sen. Bob Casey said he is still reviewing the Manchin-Toomey amendment, but that he likes what he has seen so far. It appears to be a step in the right direction, he said.
"I am a strong supporter of the Second Amendment, but I also believe we have an obligation to take common-sense steps to reduce gun violence. In the wake of the tragedy at Sandy Hook, I made very clear that I thought we have an obligation to do what we can to try to prevent the next tragedy," he said Wednesday. "This measure appears to be a major step toward that goal."
Leaders of the advocacy group CeaseFirePA agree.
"This legislation will make us safer and will keep guns out of the hands of people who should not have them," executive director Shira Goodman said.
Mr. Manchin said the Newtown shooting changed the climate in Washington and made lawmakers more receptive to background checks.
"The events at Newtown changed us all. ... It changed our hearts and minds," he said.
Washington bureau chief Tracie Mauriello: firstname.lastname@example.org, 703-996-929 or on Twitter @pgPoliTweets.