If you want to know why the Keystone Pipeline has been vetoed, here is the reason.
Venezuela has an enormous deposit of heavy sour crude that is nearly identical to the Alberta tar sands. The US oil refineries are designed especially for this heavy oil because Venezuela is nearby and before Chavez, it was politically stable.
The majority of the worlds oil refineries are designed for Arabian Light, not Venezuelan Heavy.
The Keystone pipeline would have replaced the Venezuelan oil with Canadian oil. Also the Venezuelan oil would be hard to refine and would have to be shipped a long distance if the Canadian oil displaced it and as a result, undesireable.
The veto of the Keystone pipline is to keep Chavez in power.
” Located in eastern Venezuela, north of the Orinoco River, the Orinoco Oil Belt is of a similar geographic extent as that of the Canadian oil sands. The deposits are not bitumen per se but extra-heavy oil. (Natural bitumen and extra-heavy oil are closely related types of petroleum, differing from each other only in the degree by which they have been degraded from the original crude oil by bacteria and erosion.) “