During his time as Oklahoma's attorney general, Scott Pruitt regularly sued the EPA over its regulations. Now, he operates the federal agency, and has not wasted time dismantling Obama-era environmental rules. In his FRONTLINE documentary “War on the EPA,” filmmaker James Jacoby looks at how Pruitt established himself by fighting against the EPA, and what political forces changed that allowed him to eventually become its leader. "War on the EPA" airs Oct. 11 on WNET at 10 p.m.