A display of 7-round .45 caliber handguns are seen at Coliseum Gun Traders Ltd. in Uniondale, New York.
The Senate on Wednesday rejected a bipartisan plan to expand background checks for gun buyers, dealing a sharp blow to President Barack Obama's campaign to curb gun violence after the Newtown school massacre.
Despite emotional pleas from families of victims of the Newtown, Connecticut, shootings and broad public support nationwide, the plan to extend background checks to online and gun-show sales failed on a 54-46 vote, six votes short of the 60-vote hurdle needed to clear the Senate.
The amendment negotiated by Democrat Joe Manchin of West Virginia and Republican Pat Toomey of Pennsylvania was seen as Obama's best hope to pass meaningful gun-control legislation after the December massacre of 20 children and six adults at an elementary school in Newtown.
Other measures backed by the Democratic president - including a proposal to ban rapid-firing "assault" weapons like the one used in Connecticut and a limit on ammunition magazines - also are expected to fail as the Senate conducts nine consecutive votes on gun-control legislation.
The votes are the culmination of weeks of intense negotiations and lobbying over Obama's proposed gun restrictions, and the defeat of the background checks amendment could doom the biggest package of gun legislation Congress has considered in two decades.
Opponents of the Manchin-Toomey plan and the restrictions on assault weapons said the proposals were an example of government overreach that would infringe on the constitutional right to bear arms.
The Democratic-led Senate also will consider several Republican-sponsored amendments backed by the National Rifle Association gun lobby that would expand gun rights, adding an element of uncertainty to the eventual content of the bill.
The Senate legislation also includes tighter restrictions on gun trafficking and more funding for school security.
The Manchin-Toomey background checks amendment allowed exemptions for private sales or gifts between families and friends and prohibited the creation of a national registry of guns. Polls show more than 80 percent of Americans support expanded background checks.
'SHAMEFUL SCARE TACTICS'
But the NRA had warned members the proposal would require checks for sales and gifts between family and friends and lead to a national registry, drawing complaints from supporters of the measure.
The NRA's assertions are "a lie. That is simply a lie, and anybody who can read knows that is not factual," Manchin, a strong gun-rights defender, said on the Senate floor on Wednesday.
Senate Democratic Leader Harry Reid of Nevada, also a gun owner and gun-rights defender, accused the gun lobby of "shameful scare tactics" and questioned why his colleagues would reject a proposal backed by nearly 90 percent of Americans.
He said he would "vote my conscience" and back the assault weapons ban and limits on ammunition.
"We must strike a better balance between the right to defend ourselves and the right of every child in America to grow up safe from gun violence," Reid said.
"If tragedy strikes again - if innocents are gunned down in a classroom or a theater or a restaurant - I could not live with myself as a father, as a husband, as a grandfather or as a friend knowing that I didn't do everything in my power to prevent it," Reid said.
Among the amendments offered by Republicans was one from Republican Senator Charles Grassley of Iowa that would become a substitute for the existing gun-control bill. It would focus on prosecuting gun crimes, improving mental health records for gun owners and funding improved school safety measures.
Grassley's substitute, co-sponsored by Republican Ted Cruz of Texas, would not include an expansion of background checks but would expand some gun rights by allowing interstate firearm sales.
"Rather than restricting the rights of law-abiding Americans, we should be focusing on keeping guns out of the hands of violent criminals, which this legislation accomplishes," Cruz said. "The only way to stop violent crime is to stop violent criminals."
Cruz, echoing an NRA ad running online this week, cited a survey in which most police chiefs favored more extensive enforcement of current gun laws over any effort to expand background checks.