The good news is that it's beyond the power of the EPA to turn back the clock entirely. States like Maryland have put in place their own restrictions on power plants that aim to reduce greenhouse gas emissions by levels equal to, and in some cases exceeding, those in the Clean Power Plan. Now it's up to Gov. Larry Hogan and the state legislature to stand behind Maryland's recently-upgraded mandate to reduce emissions by 40 percent by 2030 and to pressure the Trump administration to get back on board. The state is already suing the EPA over the agency's failure to regulate power plant emissions from upwind states like Kentucky and West Virginia that contribute heavily to Maryland's worst air pollution woes; it ought to legally challenge the withdrawal of the Clean Power Plan as well.