Obama Bans the Keystone XL Proposal

I wonder what would happen to the oil price of WTI if this proposal is being passed. For those who may not know what is Keystone XL pipeline, it is actually a pipeline that build for sending oil from Canada to refineries in Houston and along the Texas Gulf Coast. Yet, this pipeline is specific for sending heavy crude oil extracted from Canadian tar sands. In the perspective of simple economics, adding supply of crude oil shall lead to lower oil price. Isn't that good for US economy in general? In terms of long term perspective, I will say yes. But yet, in short term, the high oil price really helps Obama to keep on spreading the idea of green and clean energy. To make it simple, Keystone XL pipeline will be passed in the coming days. But yet, for now, lets put more focus on the green energy. 

Thanks 
Paul