A case before the Supreme Court this week that could have major implications for federal agencies’ regulatory powers will be argued by lawyers with ties to the billionaire industrialist Charles Koch, according to The New York Times. The case to be heard Wednesday is nominally about commercial fishermen who oppose a government fee they consider to be unfair. If they win, however, it could mean the end of a legal principle called the “Chevron deference”—a doctrine that gives federal agencies latitude to interpret ambiguities in laws passed by Congress. Overturning or weakening the principle, legal experts say, could restrict those agencies’ ability to regulate multiple areas including health care, finance, and the environment—as well as fisheries. According to the Times, court records show that lawyers representing the fishermen work for Americans for Prosperity, a group funded by anti-regulatory champion Koch.