Arizona Supreme Court curtails agency fact-finding deference

Phoenix, Arizona; May 15, 2026: The Arizona Supreme Court yesterday issued its opinion in Simms v. Arizona Racing Commission, holding that courts must independently review the factual findings of state agencies rather than defer to them under the so-called substantial-evidence standard. The ruling is the first of its kind in the nation.

“When an agency investigates a case, prosecutes it, and then judges it — and courts simply rubber-stamp the result — due process is a fiction,” said Adi Dynar, an attorney with Pacific Legal Foundation. “Arizona’s Supreme Court has reinforced the separation of powers by making clear that courts are not bystanders in agency adjudication; they are the final check on government power. That principle belongs in every state in the country.”

Pacific Legal Foundation filed an amicus brief in the case arguing that the substantial-evidence standard is unconstitutional when applied to agency-found facts. Under that standard, courts historically affirmed agency factual findings as long as any evidence existed to support them — even when the evidence was contradicted or when reasonable people would have made different findings.

The decision has implications far beyond Arizona.

“Dozens of states apply similar deference doctrines in administrative proceedings, leaving individuals with little meaningful judicial recourse when agencies act against them,” Dynar said. “Those deference doctrines should be revisited in light of Arizona’s ruling today.”