Here is a summary some of the [NRDC] reportís findings:
Keystone XL is a pipeline through the United States, not to it.
The vast majority of Canadaís export pipelines go to refineries in the U.S. Midwest. These refineries sell gasoline, diesel and motor oil to American consumers. Keystone XL will divert up to 830,000 barrels a day of oil from the Midwest,
sending it instead to the Gulf Coast and the international market.
Keystone XL will increase Midwestern oil prices.
[...] TransCanada has acknowledges this, estimating that Keystone XL would increase the price the United States paid for Canadian crude by between $2 billion and $3.9 billion a year.
New report: Keystone XL will undermine U.S. energy security | Anthony Swift's Blog | Switchboard, from NRDC
(links to the actual report included therein)