The forecasts are looking good for Republicans in Tuesday's congressional elections—but could one of their most powerful representatives be in trouble? In Michigan, Fred Upon, the chairman of the House Energy and Commerce Committee, may be in a tighter race than expected. His Democratic opponent, Paul Clements, released a poll this week showing him behind Upton by just four points. And while media outlets like National Journal and Talking Points Memo have been skeptical, super PACs on both sides are pumping money into the race at the last minute. 

Today, Politico reported on a new $300,000 ad buy from the American Future Fund, a group that in 2012 received 92 percent of its revenue from two groups funded by Charles and David Koch. The substance of the ad is typical, boring campaign season fodder, touting the congressman's record of cutting “job-killing red tape,” “reducing energy costs,” and “building the Keystone XL pipeline.” 

Earlier in the race, Lawrence Lessig’s Mayday super PAC promised to spend more than $2 million on anti-Upton ads, including a $650,000 ad buy this week. Here's an example of one of those ads:
The American Future Fund ad makes clear that corporations with an interest in environmental regulation, like Koch Industries, see Upton as an irreplaceable ally on Capitol Hill. The League of Conservation Voters, along with the Los Angeles Times, have noted that Upton’s once-modest record on the environment has trended more conservative in the last few years. Mayday has directly attacked Upton for his ties to "Big Oil" in several campaign ads, too.
While Clements is still a longshot, the congressional seat may be more vulnerable than both sides first thought, making this one of the more unexpected ad wars of the midterms.