WASHINGTON (AP) — Supporters of a popular energy savings bill and the controversial Keystone XL oil pipeline say they will keep trying to force Senate action on the measures, even after they were defeated amid partisan gridlock in the Senate.

The energy legislation would tighten efficiency guidelines for new federal buildings and provide tax incentives to make homes and commercial buildings more efficient. The pipeline measure would force a decision by President Barack Obama on the long-delayed project to carry oil from Canada to the United States.

Both proposals fell victim to election-year politics Monday night, as a procedural motion to end debate on the energy bill without amendments fell five votes short of the 60 votes needed for approval. The demise of the energy bill also sealed the fate of the pipeline measure. Senate Democratic leaders said the pipeline vote could occur only after Senate action on an unamended energy bill.

Sen. Mary Landrieu, a Louisiana Democrat who has pushed for the Keystone XL pipeline, took to Twitter within minutes of the Senate vote, vowing, "The fight for #KeystoneXL continues."

Landrieu said the procedural defeat was "just the latest skirmish" in a long battle to approve the pipeline, which would carry oil derived from tar sands in western Canada to Nebraska, where it would connect with existing pipelines to bring oil to the Texas Gulf Coast, near the Louisiana line.

"I've been in a lot of battles — and the ones that matter the most to people back home are the toughest," Landrieu said.

The chief sponsors of the energy savings bill, Sens. Jeanne Shaheen, D-N.H., and Rob Portman, R-Ohio, also vowed to keep up efforts to pass their bill, which they have been working on for more than three years.

"I will continue to fight for Shaheen-Portman because it's a win-win-win for jobs, clean air and taxpayers," Shaheen said after Monday's vote.

Portman called it "a sad day in the U.S. Senate" when a bill backed by more than 270 organizations —from business to environmental groups —"can't get votes on a few amendments to pass it."

Still, Portman said he would continue to work with Democrats and Republicans to try to find a way forward on the energy bill, part of a "national, all-of-the-above energy strategy."

The energy bill easily cleared a procedural hurdle last week but stalled after Republican demand for votes on the Keystone XL pipeline and on new rules proposed by the Obama administration on greenhouse gas limits for coal-burning power plants.

Republicans are united in favor of the pipeline and against the new power plant regulations, while Democrats are deeply divided on both. Senate Majority Leader Harry Reid, D-Nev., used a parliamentary maneuver to block Senate votes on the pipeline and power plant rules as part of the energy savings bill.

Reid said Republicans were "seeking a ransom" on the energy bill by insisting on the Keystone amendment and other votes. He said he had agreed to a longstanding request from pipeline supporters for a separate vote on the pipeline if its supporters would let the energy-efficiency bill sail through unamended.

Minority Whip John Cornyn, R-Texas, called Reid's action disappointing. "The Senate used to be a place of great debate and accomplishment. Now it is run like a dictatorship shutting out the voices of millions of Americans," he said.

Partisan discord was so strong that three Republican senators who co-sponsored the energy legislation voted against it Monday to protest the exclusion of amendments. Among those voting "no" was Sen. John Hoeven, a North Dakota Republican who has been the Senate's chief GOP supporter of the Keystone XL pipeline.

Democrats also said the GOP wants to deny victories for Shaheen, Landrieu and other Democrats who are running for re-election. A Senate vote on the pipeline would help Democrats who support the pipeline, even if it fell short of the 60 votes needed to advance it. President Barack Obama delayed the project indefinitely last month, citing uncertainty over the pipeline's route though Nebraska.

Landrieu, who chairs the Senate Energy Committee, angrily denounced Republicans who opposed the energy bill, a move that also blocks a Senate vote on the pipeline. "They chose to have an issue, as opposed to having a pipeline, and that's very disappointing," Landrieu said.

On the other side, Republicans accused Democrats of dodging a vote on blocking the Obama administration's proposed limits on carbon pollution from coal-fired power plants. A vote on what Republicans call Obama's "war on coal" would be uncomfortable for Democrats struggling to hold their Senate majority.

White House spokesman Jay Carney said Obama is committed to increasing energy security and efficiency and "will not rest even if Congress won't act." Obama announced a series of executive actions last week aimed at increasing energy efficiency and reducing U.S. reliance on carbon fuels.