We don't need the keystone. But the oil sands producers and the US heavy oil refineries in Texas do need it. If we were smart we would build our own refineries and sell the value-added product into the international market. But Alberta producers don't want to spend the capital. Easier just to pipe it to existing Texas refineries, who need to replace the dwindling stocks of heavy oil coming from Venezuela and Mexico. They get tar sands oil cheep (because it's tar sands),  refine it into value-added products. Some of it is sold back to Canada.  We are nothing but mugs in this game. 

Having said that I just want to remind you all that there's a little problem of greenhouse gases and climate change that's threatening humanity. Might want to pay attention to that.