The reaction was quick and predictable. Murray Energy immediately filed a lawsuit against the administration and the EPA and said it would prevail. Peabody Energy urged further action by courts, Congress, states, consumer groups and industrial/residential electricity customers to turn back the rules. Unprecedented early opposition to the rules has been advanced from members of Congress, governors, legislatures, attorneys general, and business and consumer groups.

The CPP applies to existing power plants (those that began construction on or before January 8, 2014). It asks states to develop and implement plans that ensure that the power plants achieve CO2 emissions performance rates. The agency recommended three methods for achieving its goals:
• Reducing the carbon intensity of electricity generation by improving the heat rate of existing coal-fired power plants;
• Substituting increased electricity generation from lower-emitting existing natural gas plants; or
• Substituting increased electricity generation from new zero-emitting renewable energy sources.

Several governors (Indiana, Wisconsin, Texas and Oklahoma) have already thrown down the gauntlet to President Obama and the EPA, promising not to comply with the rule unless significant changes are made to lessen its impact on low-cost energy, particularly that supplied by coal.