Actually, Obama is right to resist the pipeline. The search function (Google in this case) is your friend. All the oil companies that have contracted with TransCanada are foreign-owned except one, Valero. The foreign owned contracts are not open to scrutiny, but Valero has made their intentions clear in speeches and investment guides: They're going to refine the crude as diesel and sell it all to diesel-hungry China and South America. The other companies will most likely follow the Valero model. Diesel is in huge demand around the world. The Valero CEO expects the global demand for diesel to triple in the next couple of years. Some investment newsletters (e.g. Bloomberg) tout diesel futures as better than gold. The clincher is that the terminus of the pipeline is located in a foreign trade zone which means that any product made (refined in this case) there is exempt from all customs duties and Federal and State taxes . . . as long as it's EXPORTED! In all likelihood, nary a drop of the fuel refined there will wind up in the gas tanks of American consumers. Meanwhile, the number one export of America in 2011 was . . . you guessed it . . . oil.
TransCanada is not seeking to build the pipeline in order to get Canadian oil to the American market. They want to get it to the Gulf refineries because that's where the refineries are that are capable of turning the tar sands crude into useable transportation fuel.
Canada has three dilbit pipelines in operation already and they have a terrible track record for spills - - way more than conventional crude pipelines. And the stuff is extremely difficult to clean up.
The XL pipeline, if it's built, will be a con job. It's not going to give us any more oil, or cheaper gas, or any lasting job growth (one wag suggested that the most jobs generated by the pipeline would be oil spill clean-up employment). The only thing we'll get out of it is a significant environmental hazard.
Just sayin'.