Tar sands strip-mining in Alberta.

Should he approve Keystone XL, he risks angering a key part of the Democratic coalition, suggesting the White House could at the same time give environmentalists a policy victory elsewhere. "You can't do the Keystone pipeline and have climate change as a legacy issue for you, because the pipeline would destroy your legacy. Hopefully he understands that," said Jeff Tittel, director of the New Jersey Sierra Club. [...] Some Senate Democrats locked in tough re-election fights, among them Mark Begich of Alaska, Kay Hagan of North Carolina and Mary Landrieu of Louisiana, have said they might file legislation seeking to overturn the ruling if Mr. Obama reject the pipeline.

Numerous sources say the State Department will present its final environmental impact statement on the Keystone XL pipeline sometime in the next few weeks. Given that the delivery of the EIS will trigger a 90-day period of comments by federal agencies, President Obama could announce a thumbs up or down on the $5.2 billion project sometime in May or early June. Just in time, report Peter Nicholas and Carol E. Lee, to make his decision a factor in the 2014 mid-term congressional elections. Senate and House Republicans and not a small number of oil- and coal-state Democrats support the disputed pipeline:Keystone XL, over which thousands of protesting eco-activists and indigenous peoples of Canada and the United States have been arrested, is designed to transport up to 830,000 barrels a day of diluted bitumen from the Alberta tar sands deposits and shale oil from the Bakken formation of North Dakota and Montana to the refineries of Gulf Coast Texas where the stuff can be transformed into usable fuels.

Foes, more than 76,000 of whom have taken the CREDO pledge to be arrested to stop the pipeline, have raised various objections to it, called XL because it is 36 inches in diameter instead of the more standard 30 inches. Those objections include the threat of leaks into the nation's largest aquifer, a source of irrigation water in eight states comprising the nation's Midwest breadbasket. Leaks of diluted bitumen are dirtier and more difficult to clean up than other oil leaks. Not that aquifers are easily scrubbed no matter what they are contaminated with. But the key opposition comes from the fact that extracting and refining this unconventional source of petroleum is more carbon-intensive than for other oil.

Meanwhile, builder TransCanada announced Wednesday that it has started shipping tar sands-derived petroleum—diluted bitumen— crude oil from Cushing, Oklahoma, to customers in Nederland, Texas, via the southern leg of Keystone XL. Also called the Gulf Coast pipeline, TransCanada predicted in a press conference that the southern leg will be carrying an average of 520,000 barrels of petroleum a day by year's end. After raising the hopes of environmental advocates when he rejected the pipeline in January 2012, President Obama dashed them again a few months later with his decision to fast-track Keystone's southern leg that has now begun operations.

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