Despite the language in the tax package, Obama can kill the project and likely can still delay it. He could reject it based on the national interest argument, or he could give it a thumbs up, but delay it by awaiting a route study.

If Obama decides the pipeline is not in the national interest, “it would effectively be the end of the project,” said Johnston, although TransCanada would likely still move forward with a smaller leg of the pipeline from the Cushing, Oklahoma oil hub to Texas.

Even if Obama approves it within 60 days, he could do so conditionally by declaring the project is in the national interest, but contingent on the completion of the State Department’s study on alternative routes through Nebraska.

The State Department based its delay in November on a need to study alternative routes in Nebraska.