A member of the Center for Biological Diversity in polar bear costume protests the Keystone XL pipeline during a visit by President Barack Obama for a two-day visit to Los Angeles for two political fundraisers Wednesday, May 7, 2014. CREDIT: AP Photo/Damian Dovarganes The U.S. Senate has narrowly rejected a bill to approve construction of the Keystone XL pipeline, the controversial project that would carry tar sands oil from Alberta, Canada to refineries on the Gulf Coast of the United States. Coming into the floor debate on Tuesday, there was not certainty as to what the outcome would be — a true rarity for the Senate. At the beginning of the debate on Tuesday afternoon, bill sponsor Sen. Mary Landrieu (D-LA) said the debate was “one of the first debates I’ve been in in 8 years where the outcome is uncertain … [but] I know in my heart we have 60 votes.” As it turns out, Landrieu did not have the 60 votes to pass her bill. It failed by a final count of 59 to 41. The vote represented the first time the Keystone XL pipeline had been heard by the Senate, mainly because Senate Majority Leader Harry Reid (D-NV) had historically refused to bring the issue to the floor. But the Senate Democratic leadership changed tactics and pushed Landrieu’s “Keystone XL Pipeline Approval Act” to the floor this week in large part because of Landrieu’s drive, and also to try and save her Senate seat. Landrieu is behind in the polls for her Dec. 6 runoff election against Rep. Bill Cassidy (R-LA), and some believed the pipeline’s passage would help win her some support in the oil and gas-centered state. Environmentalists have long opposed the Keystone XL pipeline, mainly because of the type of oil it would carry. Canadian tar sands oil is more carbon intensive than other types of oil, and harder than conventional oil to clean up when it spills. Sen. Barbara Boxer, one of the strongest opponents of the Keystone XL pipeline, ripped into her pipeline-supporting colleagues for ignoring the health of communities that are located near tar sands refineries, or that live near the pipeline and are at risk from a possible spill. “Their children aren’t going to live here. Their grandchildren aren’t going to live here. They brush aside these issues,” she said on the Senate floor on Tuesday. “This is filthy, dirty, oil, with the most dangerous pollutants.” However, the Senate’s rejection of Keystone XL is more of a blow for Landrieu than it is for the pipeline project itself. Indeed, Sen. Mitch McConnell (R-KY), who is slated to be the Senate Majority Leader of the next Congress, promised soon after Tuesday’s vote that Keystone would come up again “very early” next year. The post BREAKING: Senate Rejects Keystone XL Pipeline By One Vote appeared first on ThinkProgress.