Although the New York Times notes that it’s not clear yet whether the Obama administration will allow the review process to be suspended, the request adds yet another wrinkle to an issue that has been a hot-button political topic, both in Washington and on the campaign trail.

Allowing a delay would likely push off a decision about the pipeline until after the 2016 presidential election.

So far, only one candidate for presidency has sounded off on Twitter (TWTR) about Keystone XL since the news broke:

I have always opposed Keystone XL. It isn't a distraction — it's a fundamental litmus test of your commitment to battle climate change.

— Bernie Sanders (@BernieSanders) November 3, 2015

If we are serious about combating climate change we have to do all we can to prevent the excavation of the dirtiest fossil fuels #KeystoneXL

— Bernie Sanders (@SenSanders) November 3, 2015

Sanders has made his opposition to Keystone XL a major talking point on the campaign trail as a way of shoring up his base of progressive voters.