According to this talking head on bloomberg this morning, whether the pipeline passes or not is almost a moot point as rail and the use of other pipelines and the glut in domestic supplies have taken care of the need.
It is always better to have more capacity...
A Republican President elected in 2016 might push this hard to help create jobs and the economy.
There would be 50,000 direct jobs, and probably a few indirect jobs as well.
North Dakota (and E. Montana) need more pipeline capacity.