Exports could mean higher prices in the United States for both residential consumers of natural gas -- about half the country uses it to heat their homes -- and industrial users, which have begun relocating to the United States after years of outsourcing to take advantage of the low gas prices.
If exports are allowed from all the proposed facilities, natural gas prices could rise between 9% and 32% over the 2015 to 2025 time frame, according to the U.S. Energy Information Administration.
That "could potentially have catastrophic impacts on U.S. manufacturing," said a report on the matter from House Democrats on the Natural Resources Committee.
But the biggest sticking point for opponents is that exporting natural gas may increase fracking in the United States.
Fracking involves injecting vast amounts of water, sand and some chemicals deep into the ground at high pressure to free the gas.
The industry maintains it's safe, but many in the environmental community fear it's contaminating the ground water.
The Sierra Club, along with other opponents, is asking the government to consider the broader environmental impacts of fracking, as well as to evaluate Cheniere's job claims.
The Energy Department has already granted Sabine Pass a permit, although it has promised to consider other impacts on the economy and environment before approving any of the remaining seven proposals.
The Federal Energy Regulatory Commission is expected to vote on the matter later this month, and approval seems likely.
Frustrated, the environmental groups have taken their case all the way to the President, filing letters with the Environmental Protection Agency and the White House Council on Environmental Quality asking them to intervene. EPA said it is reviewing the request. The White House didn't respond to a request for comment.
For now, it appears Cheniere will get its way.
"We don't believe [the] opposition is loud enough yet to change the current course," Whitney Stanco, an energy analyst at the Washington Research Group, wrote in a recent note.
But she did note that environmentalists were successful in a last-minute drive to block the Keystone pipeline.
"We'll be watching the level of opposition closely," she said.