The Keystone XL Pipeline would take crude oil from the tar sands in Canada through Montana, South Dakota and Nebraska and connect to existing pipelines that carry oil to refineries on the Gulf Coast.
The Senate on Thursday night passed a bill forcing its approval, even though President Obama has threatened to veto it. The House approved a similar bill earlier.
The argument over the pipeline has gotten increasingly heated over the last five years and as, Coral Davenport writes in the New York Times, "has become a proxy for far broader fights over climate change, energy and the economy."
Environmentalist have seized on it, and attacked the project, arguing the process of extracting oil form the Canadian tar sands is expensive and energy intensive. Those in favor say the Keystone XL will create a lot of jobs and pump billions into the economy.
Davenport says there is a little truth to each argument but that most experts agree that the effects, should the pipeline happen, will be negligible when it comes to the job market or climate change.