The vote was set at a filibuster-proof 60 vote threshold -- a rare case where the party in power uses the tool to deny a Senate majority from passing legislation by a majority vote.
"I would hope that this gun amendment would not get the 60 votes required, because I believe it is dangerous," said Sen. Barbara Boxer (D-CA), the sponsor of the water resource legislation, prior to the vote. "Why would we want to have on a water infrastructure bill an amendment that allows people to come in with guns and go right to the heart of those critical water infrastructure projects, those dams, those reservoirs, those locks?"
The Democrats who voted for the bill were Sens. Max Baucus (MT), Mark Begich (AK), Joe Donnelly (IN), Kay Hagan (NC), Martin Heinrich (NM), Heidi Heitkamp (ND), Joe Manchin (WV), Mark Pryor (AR), Jeanne Shaheen (NH) and Jon Tester (MT).
Sen. Mark Kirk (IL) was the only Republican to vote against it.
Coburn's office compared it to a 2009 measure brought by the senator to allow guns in national parks, a bill that passed 67-29 and was signed into law by President Obama.
Even though it failed, the vote is an eye-opening reminder that even amid the strongest effort in Congress to tighten gun laws in two decades, a majority of the Democratic-led Senate continues to support expanding gun rights. Passage of the Coburn measure would have been an embarrassment for gun control supporters.