Opponents of the Keystone XL pipeline delivered more than 2 million comments Friday urging the Obama administration to deny the project, roughly twice the number that supporters submitted.

The disparity between the two camps, which came on the final day the State Department was accepting public comments on whether the pipeline serves the national interest, underscores the complex nature of the administration’s upcoming decision. While Americans back approval of the pipeline by a nearly 3 to 1 margin, according to a new Washington Post/ABC News poll, many young people and liberal Democrats intensely oppose it on the grounds that it would accelerate climate change and could lead to dangerous spills.

“We’re hearing from people all across this country who know that the Keystone XL pipeline is absolutely not in our nation’s best interest,” said Amanda Starbuck, the Rainforest Action Network’s climate program director, in a statement.