From CNBC:
With oil closing below $50 on Thursday, the lowest price since March, Cramer thinks that the U.S. needs all of the pipelines it can get. Oil transport by train costs $13 more per barrel than oil by pipe, thus with crude at these levels pipelines are especially needed.
It is clear to Cramer that the lower price of oil or gas will impact the MLPs that have direct exposure to pricing the most, and that is the minority of the group.