President Barack Obama had sought to delay judgment on the approval of the Keystone XL pipeline project for carrying tar sands oil from Alberta in Canada down to the Gulf Coast refineries. Obama realized that this was a wedge issue for the Republicans. The environmentalists, a key component of the Obama coalition, strongly opposed the pipeline because they feared an environmental disaster and objected to the exploitation of tar sands as a source of energy. On the other hand, the pipeline would have created tens of thousands of jobs, a particularly sensitive topic in this year's elections. Additionally, Canadian oil...