In this particular case, it is the Clean Air Act, enacted by Congress in 1972.
And in this particular case, in 2007, SCOTUS ruled that CO2 was a pollutant(Massachusetts v EPA) and told EPA to regulate CO2 with the Clean Air Act.
Congress had their shot at this in 2009 when they attempted and failed to pre-empt EPA with a Cap and Trade program. The GOP could stop Obama and the EPA tomorrow by passing legislation to regulate CO2, after which the PREZ and EPA would have to implement, administer, and enforce that act of congress.
Is the prez supposed to implement, administer, and enforce unconstitutional laws that arise from Congress and the Judiciary? For example, the constitution says that if Congress passes gun control or a judicial decision somewhere creates such necessary law, the president is constitutionally obligated to use the federal government to implement, administer, and enforce it? With a new executive agency, if need be?
Something is wrong with that picture when you are voting for a Republican willing to go along with that, and Obamacare, and Global Warming EPA tyranny.
I finally figured out why there are currently TWENTY FIVE probable total Republican primary candidates with 15 declared, 10 still exploring, including Walker, Jindahl, Christie, Jeb, and Trump, for pete's sake.
This versus a Democrat party whose contemporary primary field is TEN, seven declared, 3 "exploratory."
Republicans are deeply confused.