Ask progressives what the last three weeks of Senate debate on a Keystone XL bill was really about, and they might mention the Koch brothers. “The Republican's Keystone XL obsession is about one thing and one thing only—a direct payback to Big Oil, specifically to the Koch brothers,” Credo’s Senior Campaign Manager Elijah Zarlin said in response to the Senate passing a Keystone XL bill, 62-36, on Thursday.

It's not just a talking point. Just one month into the new Congress, and already the Kochs' fossil fuel interests—which include oil pipelines and refineries—have neatly aligned with Republican priorities. The Koch network's campaign for and against Keystone amendments not only offers a preview of future energy battles, but demonstrate their difficult-to-quantify political influence.

In January, three conservative groups—Heritage Action, American Energy Alliance (AEA), and Americans for Prosperity (AFP)—combined for a total of seven key vote alerts on amendments that would count in their congressional scorecards. The alerts serve as a warning: If a senator votes against the group's interest, he or she risks future attacks from the right. All three groups are tied to the Kochs: AFP is considered the brothers' "main political arm," and they have contributed to Heritage and AEA.

The groups helped defeat an amendment from Heidi Heitkamp, a North Dakota Democrat, that would have reinstated the wind production tax credit for five years. Heitkamp couldn't even scrape together a majority of senators for what historically has been a popular, bipartisan policy. Wind energy happens to be big in red states, so it has the support from Republicans like Iowa's Chuck Grassley, but it has long been a target for conservative, fossil-fuel-aligned groups. AEA, AFP, and Heritage all recommended a "no" vote on the amendment, in line with the Koch network's years-long campaign to eliminate renewable tax credits (while oil's tax breaks remain politically untouchable).