President Obama is secure in his second term. For environmental groups concerned that an alternative result to the 2012 elections would have meant the dismantling of the Environmental Protection Agency (EPA), January’s inauguration was an undoubted relief. These groups may now turn their attention to the unmitigated expansion of the EPA regulatory apparatus, eyeing the regulation of existing stationary sources of Greenhouse Gas Emissions (GHG). The movement to regulate these facilities is much messier than many pundits are prepared to admit and is an important reminder of agency limits.

In 2012 the EPA published its emissions standards for new stationary sources. This rule sets standards for factories and other facilities that emit harmful pollutants such as greenhouse gases. Mandating caps of 1,000 pounds of carbon dioxide per megawatt-hour, this rule places such heavy restrictions on emissions that it likely means the permanent shelving of future coal facility development. These standards currently omit existing stationary sources of emissions, however, creating an expectation that these facilities that predate the final rule will soon fall prey to similar restrictions.

This expectation is bolstered by language in the rule, which describes itself as precursor to further regulation. The regulation is alluding to a perceived requirement of the Clean Air Act’s § 111(d) that any existing stationary sources of emission must soon be brought into accord with regulation of emissions applicable to new sources.

For environmental groups this language has provided valuable ammunition in the fight to secure increased emission regulation. The popular belief among these circles is that the expansion of regulation to existing facilities was deemed too politically toxic to touch during the campaign season but with reelection secured, the EPA will now be permitted to move forward on extending these new stationary source standards to facilities already up and running.

The trouble, as a new Federalist Society paper attempts to remind these eager proponents of regulation, lies in the law. Clean Air Act’s §111(d), the same section that advocates argue mandates matching regulations for these existing sources also explicitly states that existing sources are not to be regulated under that title when they are already regulated by the act’s companion § 112. The EPA has already used §112 to regulate existing facilities, promulgating the ‘Utility MACT’ rule under this section.The Federalist Society argues that this statutory restriction is an unambiguous congressional refusal to permit the EPA from double-dipping existing facilities in their murky regulatory pool.

The debate sure to ensue over any attempt to regulate existing stationary source emissions therefore promises to be necessarily dense in its legalese, likely to be left to a court to decide the legislative intent of congress, and as a result escapes the purview of this post. This is, however, precisely the point.

The conversation must remain focused on this statutory disagreement because federal agencies are bound to the authority granted to them by statutory law. Much attention, and no shortage of excitement, assumes the EPA’s ability to regulate. The very real complexity of the issue is instead a snapshot of the constitutional system of ensuring no single branch of government monopolizes federal power. Today’s EPA forecast? Cloudy. Somewhere James Madison is smiling.