WASHINGTON (AP) - Long-stalled legislation to build the Keystone XL pipeline got new life on Wednesday after Senate Democrats suddenly abandoned efforts to block the measure in hopes of helping endangered Sen. Mary Landrieu keep her seat in energy-rich Louisiana.
Republicans responded swiftly to Landrieu's maneuvering, scheduling a vote in the House on Thursday on an identical bill sponsored by Rep. Bill Cassidy, Landrieu's Republican rival in a Dec. 6 runoff.
While the White House stopped short of directly threatening a veto, spokesman Josh Earnest said President Barack Obama takes a "dim view" of legislative efforts to force action on the project. Earnest reiterated Obama's preference for evaluating the pipeline through a long-stalled State Department review.
Republicans and several moderate Democrats insist that construction of the Canada-to-Texas pipeline would create tens of thousands of jobs. Environmentalists maintain that the project would have a negative impact and contribute to climate change.
"I believe that we should take the new majority leader at his word and stop blocking legislation that is broadly supported by the American public and has been for quite some time," Landrieu said in a speech on the Senate floor. "I want to say yes to majority leader - new majority leader Mitch McConnell. The time to start is now."
Landrieu cast herself as an independent willing to challenge Democrats and Republicans, hoping to shake up her Senate race.
"I've stood against my leadership," she told reporters, and added, "And I've stood up to the Republicans."
The back-and-forth came against the backdrop of a new political landscape and fresh calls for an end to Washington gridlock. Republicans rolled in midterm elections, seizing majority control of the Senate with a net gain of eight seats. A GOP victory in Louisiana would make it nine and Cassidy is heavily favored.
Come January, Republicans could have a 54-46 majority in the Senate if Cassidy wins, controlling the chamber and legislation for the first time in eight years.
McConnell said the election of a Republican Senate majority has already changed the dynamic.
"I hope this post-election conversion on Keystone signals Democrat cooperation on a whole host of other energy bills they have blocked, and whose passage would help to make America more energy-independent," he said in a statement.
Echoing Landrieu's plea for a vote were moderate Democrats from Republican states, who argued that the project that would carry oil from Canada south to the Gulf Coast. The southern leg of the pipeline between Oklahoma and Texas is already operational.
Senate Majority Leader Harry Reid, D-Nev., has moved in the past to prevent the Keystone measure from passing, giving credence to Republican claims that Landrieu is ineffective as chairman of the Energy and Natural Resources Committee.
The Republican sponsor of the bill, Sen. John Hoeven of North Dakota, said the measure has the support of all 45 Republicans and 11 Democrats. It will be incumbent upon Landrieu to persuade four more Democrats to back the measure to reach the 60-vote threshold.
One senior Senate Democratic aide said Reid would not attempt to defeat Landrieu's effort.
Asked if Obama would sign it, Landrieu told reporters: "I do not know."
Energy has been a central issue in the Senate race, and Keystone a frequent flashpoint with both Landrieu and Cassidy supporting the project. Cassidy has said Landrieu has been unable to deliver because of her party's leadership.
Landrieu has a strong alliance with the oil and gas industry and has pushed for an expansion of drilling in the U.S.
If elected, Cassidy would get a seat on the Energy panel. As a new senator, he would be low in the pecking order of panel members, and in the final two years of Obama's presidency, Cassidy and Louisiana's all-GOP congressional delegation would likely have little sway with the Democratic administration.
As Louisiana's last Democratic statewide elected official, Landrieu has a difficult path to victory in a state that overwhelmingly backed Republican presidential nominee Mitt Romney in 2012. Fifty-eight percent of voters supported someone other than Landrieu in the primary last week.
Republican leaders are uniting behind Cassidy, a three-term congressman, while the national Democratic Party has decided against providing advertising support for Landrieu in the runoff.
Asked if she was a lost cause, Landrieu told reporters, "No, I don't believe that I am."
In a statement, Cassidy said it "is easy to wonder if the Senate is only considering this because of politics, even so, I hope the Senate and the president do the right thing and pass this legislation creating thousands of jobs."
Associated Press writer Melinda Deslatte in Baton Rouge, Louisiana, contributed to this report.