In Southaven, Mississippi, xAI installed and is illegally operating 27 unpermitted gas turbines as part of its Colossus Gas Plant, built to power the AI chatbot, Grok. To satisfy the bot’s massive power demands, these turbines are pumping air pollution into a nearby residential community, creating noise and smog while driving up health risks.

The NAACP and its local affiliate sued xAI in the United States District Court for the Northern District of Mississippi on behalf of their members in the affected community for violating the Clean Air Act. The plaintiffs invoked the Clean Air Act’s citizen-suit provision, which allows injured persons to initiate a lawsuit against polluters.

Instead of stepping in to enforce the law, the government is trying to intervene to get the lawsuit dismissed. Deeming the district court’s failure to rule (thus far) on its motion to intervene a “constructive denial” of that motion, the government appealed to the United States Court of Appeals for the Fifth Circuit and asked the court of appeals to stay all proceedings until the intervention question is resolved. Among other things, the government is arguing that allowing this Clean Air Act suit to proceed over the government’s objection would run afoul of the executive branch’s exclusive enforcement authority under Article II of the Constitution.

In October 2026, the Constitutional Accountability Center filed an amicus brief in the Fifth Circuit in opposition to the government’s motion for a stay pending appeal. Our brief explains that Article II poses no bar to citizen suits and makes two principal points.

First, the private enforcement of public laws was common at the Founding, and no one  raised constitutional objections at the time. Drawing on centuries of English law permitting enforcement by “informers”—uninjured private individuals who filed suits for statutory penalties against violators of laws passed to further the public welfare, the colonists enacted dozens of laws with informer provisions in their colonial assemblies. After independence, state legislatures relied heavily on informers to enforce new fiscal and regulatory regimes. And in the decades after the Constitutional Convention, Congress and the state legislatures enacted countless new statutes with informer provisions. During this period, courts also regularly adjudicated suits by informers without expressing any concern that such actions infringed on Article II, even though informers initiated and terminated these suits with limited oversight from the executive branch.

Second, vigorous private enforcement continued throughout the nineteenth century, though informers eventually fell out of favor when they grew less effective. These nineteenth-century statutes deputized informers against a wide range of public ills, from traditional areas of penal enforcement to cutting-edge new regulatory schemes. Notably, both Congress and the states relied on informers to enforce early environmental-protection schemes. While a confluence of factors, including shifts in public opinion and default rules of evidence, caused informer statutes to fall out of favor toward the end of the nineteenth century, it was not because of some sudden constitutional revelation. Rather, it was because informers simply had grown less effective as tools of enforcement.

The United States’ constitutional objection to this suit is impossible to square with the fact that informer’s statutes—which looked much more like private individuals acting as public prosecutors than the Clean Air Act—were prolific, yet never questioned on Article II grounds, throughout the nation’s history.