Bill Cobb says regulatory lawyers told him he’d have a tough time challenging the U.S. Environmental Protection Agency when it disapproved of Texas’ plan to regulate air quality under the Clean Air Act (CAA).

Yet Cobb, who represented Texas, and Samara Kline, who represented 10 private industry clients, fought the EPA and won a ruling from the 5th U.S. Circuit Court of Appeals that vacates the EPA’s decision disapproving of Texas’ State Implementation Plan (SIP).