A divided US Supreme Court threw out a decades-old legal doctrine that empowered federal regulators to interpret unclear laws, issuing a blockbuster ruling that will constrain environmental, consumer and financial-watchdog agencies.
The 6-3 decision raises new questions about longstanding rules and puts more of the onus on Congress to directly tackle policy issues with new laws. It gives judges a broader mandate to rein in regulators when they exceed their authority.
The ruling, which came in a fight over a fishing-industry regulation, is a long-sought triumph for opponents of big government. The court overturned Chevron v. Natural Resources Defense Council, ...