“You can’t fight City Hall.”

While this famous phrase is ­believed to have its origins in the political corruption of the ­mid-1800s in New York City’s Tammany Hall, it can also be used to describe the steep climb faced by corporate counsel when challenging a government agency in the promulgation of regulations. But don’t tell that to the nation’s energy industry. Indeed, the energy industry is at the very center of several high-profile cases challenging the statutory authority and processes used by the U.S. Environmental Protection Agency (EPA) and the Pennsylvania Department of Environmental Protection (DEP) in promulgating sweeping new regulations on energy production. In doing so, the industry is blazing a new trail in the fight against regulatory overreach that corporate counsel in all industries would be wise to monitor.