The Supreme Court on Friday dramatically clawed back power from federal regulators by overturning decades of precedent that had been set in the 1984 Chevron v. Natural Resources Defense Council case.

In a 6-3 decision that again split along ideological lines, the high court ripped up the Chevron precedent, which called for judicial deference to agencies in situations where the law is unclear.

As a result, it will become much easier for the court system to overrule regulations and for judges to issue their best interpretation of the law.

“Courts must exercise their independent judgment in deciding whether an agency has acted within its statutory authority,” Chief Justice John Roberts wrote in the majority opinion. “Careful attention to the judgment of the Executive Branch may help inform that inquiry. And when a particular statute delegates authority to an agency consistent with constitutional limits, courts must respect the delegation, while ensuring that the agency acts within it.”

“But courts need not and under the APA [Administration Procedure Act] may not defer to an agency interpretation of the law simply because a statute is ambiguous.”