I am not familiar with the pipeline you are talking about, but most of the controversial pipelines I know about are (or were) being built to export natural gas to other countries (where the price is much higher).

The US does not import much from Russia at all: most of the natural gas used in the US comes from cheap US and Canadian sources. US and Canadian gas exporters would prefer to ship their gas to other countries that would pay them more. Obviously this would not be great for natural gas consumers in the US.