How a Fishery Case Fits Into a Long-Game Effort to Sap Regulation of Business

The Supreme Court heard arguments on Wednesday in a set of cases that could pave the way for its conservative supermajority to undercut how American society imposes rules on businesses, advancing a key goal of the conservative legal movement.

Such a ruling would make it easier to challenge regulations across a gamut of issues, like keeping the air and water clean; ensuring that food, drugs, cars and consumer products are safe; and much more.

The court is expected to issue its ruling by the end of its term, most likely in June. But it remains unclear how sweeping any ruling — and its consequences — would be. Here is a closer look:

What is at issue?

The plaintiffs in the case are asking the Supreme Court to overturn a major 1984 precedent, Chevron v. Natural Resources Defense Council. The decision lays out a framework that federal judges — especially at the district and appeals court levels — have used for decades to resolve the myriad legal challenges to regulations.

People who do not like particular rules can file lawsuits arguing that an agency exceeded the limits of the authority Congress granted to it. According to the precedent established in Chevron, if part of the law Congress wrote empowering a regulatory agency is ambiguous but the agency’s interpretation is reasonable, judges should defer to the agency.