Is ‘common sense’ a legal standard? If so, anything goes

If you think federal regulators care about data-driven, evidence-based policymaking, a case currently before the U.S. Court of Appeals for the 11th Circuit will leave you scratching your head.

The case involves a terrible Biden administration regulation driven by Big Labor. In defending this regulation, which mandates that crews on freight trains include at least two people, attorneys for the U.S. Department of Transportation leaned heavily not on data or evidence but on “common sense.”

This...