Four politically vulnerable Senate Democrats are urging U.S. President Barack Obama to approve the Keystone XL pipeline, spotlighting the implications of an election-year decision that may influence which party controls the chamber. At a rally yesterday in Washington, Senators Mary Landrieu of Louisiana and Mark Pryor of Arkansas joined Republicans, the Canadian ambassador to the U.S., oil-industry lobbyists and labor leaders to call on the administration to authorize the $5.4 billion Canada-U.S. oil pipeline. Two other Senate Democrats who face tough November re-elections — Mark Begich of Alaska and Kay Hagan of North Carolina — weren’t at the rally but also have voiced strong support for the project. “The president is in a bit of a squeeze on this,” said Stu Rothenberg, editor of the nonpartisan Rothenberg Political Report. Rejecting Keystone will give Republicans running against the four Democrats a “green light” to attack over a project that’s popular […]