The vote was 58-39 in favor of the provision establishing concealed carry permit reciprocity in the 48 states that have concealed weapons laws. That fell two votes short of the 60 needed to approve the measure, offered as an amendment to a defense spending bill.
Opponents prevailed in their argument that the measure violated states rights by forcing states with stringent requirements for permits to recognize concealed weapons carriers from states that give out permits to almost any gun owner.
"This is no minor shift in policy," said Sen. Dianne Feinstein, a Democrat whose state of California requires people to be fingerprinted, get gun training and to undergo a federal background check before issuing permits. "It in fact would be a sweeping change and I think with some deadly consequences."
The vote reversed recent trends where Republicans and gun rights Democrats from rural states joined to push pro-gun rights issues and block gun control legislation.
Congress this year voted to restore the rights of people to carry loaded weapons into national parks and the Senate moved to effectively eviscerate the tough gun control laws of the city of Washington.
Congress has also ignored urgings from President Barack Obama and Attorney General Eric Holder to revive a ban on military-style weapons that expired in 2004.
The concealed weapons measure, promoted by the National Rifle Association and Gun Owners of America, would have made a concealed weapon permit from one state valid in the 47 other states with permit laws. Only Wisconsin and Illinois have no carry permit laws.
Sen. John Thune, a Republican from South Dakota, the sponsor, said it would not provide for a national carry permit, and that a visitor to another state would have to obey the limitations of that state, such as bans on concealed weapons in restaurants or other places.
"Law-abiding individuals have the right to self-defense," even when they cross state lines, Thune said, citing the example of truck drivers who need to protect themselves as they travel.
Opponents, however, said the 48 states with permits have a broad range of conditions for obtaining those permits: some such as Alaska and Vermont, give permits to almost all gun owners. Others, such as New York, have firearm training requirements and exclude people with drinking problems or criminal records.
Among the opponents were 450 U.S. mayors who signed a full-page add in USA Today, say the bill, if passed, will put police and citizens in greater danger,.
"This is about as anti-police, pro-gun trafficker piece of legislation that has ever come before the United States Senate," said New York Mayor Michael Bloomberg Tuesday.
Sen. David Vitter, a Republican and another sponsor, reminded his colleagues that the NRA and Gun Owners of America were scoring the vote, meaning it would be considered in their election evaluation of lawmakers.
NRA chief lobbyist Chris W. Cox said the last two decades have shown a strong shift toward gun rights laws. "We believe it's time for Congress to acknowledge these changes and respect the right of self-defense, and the right of self-defense does not stop at state lines," he said.
Gun control groups were strongly in opposition.
The Brady Campaign to Prevent Gun Violence said Mississippi residents can get a permit without any training, including ever shooting a pistol on a range. These permit holders could carry firearms in New York City, where police have broad discretion to deny permits, or Dallas, where permit applicants must undergo at least 10 hours of training.