The Senate on Tuesday narrowly rejected a bill to fast track construction of the Keystone XL pipeline, with supporters of the bill falling just one vote short of the 60 votes needed for passage.
The bill failed by one vote, with a final tally of 59 to 41.
The loss could be a blow for Sen. Mary Landrieu, a Louisiana Democrat and cosponsor who pushed the Democratic leadership to put the bill up for a vote in recent days. Their decision to do so was largely seen as a move to help her win re-election to her Senate seat in a Dec. 6 runoff. Polls show her trailing her opponent, Rep. Bill Cassidy, R-Louisiana.
In the hours before the vote, Republicans indicated that they wanted to put the onus on President Obama to make a final decision. Had the bill passed, the House version with identical language would have gone to his desk for a signature.
Sen. Pat Roberts, R-Kansas, said the president, "owes the American people an answer as to whether he supports this project or not."
But the delay is likely to only postpone the inevitable for Mr. Obama. In January, Republicans will take over the Senate with at least a 53-seat majority. That figure will rise to 54 if Landrieu loses to Cassidy, who authored the House's Keystone XL bill that passed last week.
After the vote, Senate Minority Leader Mitch McConnell, R-Kentucky, pledged it will be "an early item on the agenda in the next Congress" and predicted it would pass.
The bill's failure came down to insufficient Democratic support. Fourteen Democrats joined their Republican colleagues in voting for the bill: Sens. Landrieu, Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Mark Pryor of Arkansas, Claire McCaskill of Missouri, Jon Tester and John Walsh of Montana, Mark Warner of Virginia, Kay Hagan of North Carolina, Mark Begich of Alaska, Joe Donnelly of Indiana, Bob Casey of Pennsylvania, Tom Carper of Delaware and Michael Bennet of Colorado.
Several lawmakers in the hours beforehand expressed their opposition on the Senate floor.
"It's just plain dangerous because it will transport the dirtiest oil on the planet. Forcing the approval of the Keystone [pipeline] when so many concerns remain does not allow for the kind of review that our affected communities deserve," said Sen. Barbara Boxer, D-California, Tuesday. "To stand here and say this is the absolute job producer is phony. It is phony baloney."
She warned that, "To go blindly down this path is a huge mistake."
Sen. Barbara Feinstein, D-California, said, "On the economics of the pipeline, there is simply not enough benefit to outweigh the environmental damage."
Some Democrats who have indicated they are "yes" votes found themselves the subject of protests by climate groups Tuesday afternoon. They carried banners to Carper and Bennet's offices and accused the two senators of voting like climate change deniers.
Immediately after the bill failed, Cassidy went on the attack against Landrieu.
"Senator Mary Landrieu's failure to pass the Keystone XL Pipeline this evening is a perfect snapshot of her time as Chair of the Energy Committee - a failure," he said in a statement. "Conversely, Dr. Cassidy passed the Keystone pipeline out of the House last week with wide bi-partisan support. Ironically, while Senator Landrieu was failing on Keystone for the past 6 years, she was simultaneously campaigning on her supposed 'clout."
The proposal passed by the House Friday says that TransCanada can construct and operate the pipeline. Crude oil harvested from Canadian tar sands would be carried by the pipeline to oil refineries along the U.S. Gulf Coast.
The project has been delayed for several years by the State Department's environmental review process. Its analysis, released in January, found the project would pose no "significant" environmental danger. In April, however, Mr. Obama's administration indefinitely extended the amount of time agencies have to review the project, citing continued legal wrangling over the pipeline's route through Nebraska.
If signed into law, the bill passed by the House would have effectively ended the debate over the project's environmental impact. It would recognize the State Department's analysis as the final verdict on the matter and clear the way for construction to begin.