Leave it to the Obama Environmental Protection Agency to plumb the heretofore untested depths of regulatory legerdemain to justify their environmentalist central planning.

The Obama administration’s forthcoming regulations on existing power plants — i.e., the main course of their proffered climate-change menu, set for release this week — were always going to spark a whole host of legal challenges no matter what provisions they used for their justification. The negative economic impact the new rules will have on a bunch of states and industries is certainly going to make it worth their while, and part of the EPA’s task in devising the rules was to find the best way possible to protect them from these challenges.

Evidently, they think they’ve found it. Via the WSJ:

The expected legal battle over the Obama administration’s coming limits on carbon emissions from existing power plants could provide a rarity for environmental litigation: a case for which there is scant court precedent.

The Environmental Protection Agency is turning to a little-used provision of the Clean Air Act for its new rules, because carbon dioxide isn’t regulated under major Clean Air Act programs that address air pollutants. The EPA says it has only used the section, called 111(d), to regulate five sources of pollutants since the provision was enacted in 1970—and none on the scale of CO2, a major greenhouse gas.

Because the provision has been invoked so rarely, courts have had little opportunity to weigh in on it, creating the unusual circumstance in which potential challengers to the carbon rules would be litigating largely on a blank slate against the EPA. The Clean Air Act provision gives the agency authority to regulate pollutants emitted by facilities already in operation, but the expected lawsuits from states and industry could test how far a president can go in using the long-standing air-pollution law to try to address climate change.

Unfortunately, the EPA has been on something of a legal winning streak lately, and the eco-radical lobby is in a tizzy of excitement over these latest and greatest regulations. The Obama administration has been in preemptive defense mode, and we can all look forward to a whole lot more of this over the coming days: