@Caddyman ; There has been a major shift in US oil and gas production. Oil used to come mostly from Texas, and shipped North to refineries in the industrial Mid West. We now have huge refing capacity in the Gulf area and increasing oil production in the North (North Dakota, Minnesota, etc) as well as increasing IMPORTS from Canada.
The XL pipeline is needed to move oil from North to South where most of the refineries are. It will transport Candian crude oil as well as US oil from the Northern states. The state of Nebraska rightfully wanted some changes in the route, and the company has already complied. The main reason for Obama postponing the decision (not necessarily promising the permit) till after the election was all those environmental and other protest groups parading in front of the White House. And, of course the Hollywood/California media.
In fact, the part to be approved was only a few feet; the part that crosses the US-Canadian border. The US section itself was already permitted, and the Canadian government had already approved the Canadian section. The federal government had jurisdiction only because th line crossed an international border.
Older US refineries in the Mid West are gradually being shut down, and refined product is shipped by product pipeline from the South. The US imports about 50% of its oil, mostly from Canada and Mexico, as well as Africa and the Middle East. Venezuela used to be a major supplier. That oil is now going mostly to China. Contrary to popular belief, the US is not an net exporter of refined products, some are shipped to Mexico which has a tight refining situation. That amount dwarfs what the US IMPORTS from Mexico in the form of crude oil. The East Coast also imports large amounts of finished product (gasoline, diesel, jet fuel) from overseas.
Minnesota producers are now shipping oil by RAIL to the Gulf Coast since pipeline capacity is so stretched!