US President Barack Obama's campaign to curb gun violence after the a school massacre in Conneticut was dealt a crippling blow on Wednesday as the Senate rejected a plan to expand background checks for gun buyers.
Despite emotional pleas from families of victims of the shootings at Sandy Hook Elementary School in Newtown and broad public support, the plan to extend background checks for sales made online and at gun shows failed on a 54-46 vote, six short of the 60 votes needed to clear a procedural hurdle in the Senate.
It was a stark reminder of the gun culture's hold on America - or at least its politics - and a display of how each party has used Senate rules to effectively block legislation even when it has the support of the majority, Reuters reports.
At the White House, a visibly angry president said on Wednesday that he sympathised with Americans who were trying to make sense of it all.
"This was a pretty shameful day for Washington," said Mr Obama, flanked by Newtown families and former US Representative Gabrielle Giffords, who was severely wounded in a mass shooting in Arizona in 2011.
"I see this as just round one," the president said. "Sooner or later, we are going to get this right. The memories of these children demand it."
The plan by Democrat Joe Manchin of West Virginia and Republican Pat Toomey of Pennsylvania to expand background checks represented Barack Obama's best hope to pass meaningful gun-control legislation after the killings of 20 children and six adults at Sandy Hook Elementary School in December last year.
Other measures backed by Mr Obama - including a proposal to ban rapid-firing "assault" weapons like the one used in Connecticut and a limit on ammunition clips - also failed in a series of Senate votes that reflected senators' reluctance to be seen as undermining the constitutional right to bear arms.
The votes also showed the enduring political power of gun-rights defenders and the National Rifle Association, the nation's largest gun lobby.
"Our hearts are broken. Our spirit is not," Mark Barden, whose son was killed in Newtown, said at the White House after the vote. He vowed that his group of Sandy Hook victims' family members would continue to seek "common-sense solutions" to gun violence.
The votes in the Democratic-led Senate on Wednesday were the culmination of weeks of intense negotiations and lobbying over the proposed gun restrictions, and signaled the likely demise of the biggest package of gun legislation in Congress in 20 years.
The political momentum for new gun-control laws had dissipated after December's shooting. Opponents criticised the proposals as government overreach that would infringe on citizens' gun rights under the US Constitution's Second Amendment.
The NRA mounted an aggressive lobbying effort that Barack Obama said amounted to a series of "lies" and "scare tactics" about the potential impact of gun legislation.
"Expanded background checks would not have prevented Newtown," Republican Senator Charles Grassley of Iowa said on Wednesday in opposing the Manchin-Toomey plan.
The president said senators were too worried that a "vocal minority" of gun owners would make them pay in the next election for their vote to support the gun-control amendments.