The US District Court for the Northern District of Missouri on Monday rejected the Trump administration’s attempt to dismiss a lawsuit filed by the National Association for the Advancement of Colored People (NAACP) against xAI and MZX Tech.

Judge Debra Brown said that the Clean Air Act (CAA) gives the administrator of the EPA the unconditional right to intervene in the lawsuit but that the Trump administration may not properly dismiss the lawsuit. First, discussing Federal Rule of Civil Procedure (FRCP) 41(a)(1)(A), the court held that that rule is properly read as the dismissal of one’s own action, not other plaintiffs’ actions. Therefore, the government could not invoke the rule to dismiss the NAACP’s suit.

Moving onto the CAA, the only other source of the government’s alleged right to dismiss, Judge Brown wrote that “the EPA’s role as a primary enforcer of the CAA does not mean that the federal government retains complete control over all Clean Air Act litigation.” The Act provides one instance where the US government may preclude a citizen suit, but that instance has to do with the EPA’s prosecution of a civil action to require CAA compliance. This was not the case here.

The court also found the case law unpersuasive for the government, finding that “[b]ecause the Administrator has not taken any action to enforce the Clean Air Act here, [the cases cited] do not support the United States’ position.”

Finally, Judge Brown held that the canon of constitutional avoidance did not allow the court to “invent a right that does not exist” in the CAA. She did not find the CAA’s citizen suit provision was incompatible with Article II of the Constitution, which vests the executive power in the president.

The NAACP sued xAI in April, arguing that it and its subsidiaries failed to acquire mandatory permits to build gas power plants for data centers in the greater Memphis area, which has a significant Black population. Between August and December 2025, according to the complaint, xAI and its subsidiary, MZX Tech, “installed and began operating twenty-seven polluting gas turbines” in Mississippi without obtaining the required permits under the CAA.

The US, on behalf of the Administrator of the Environmental Protection Agency (EPA), moved to intervene and dismiss the lawsuit in June, arguing that the NAACP is attempting to thwart the executive process:

Through a citizen suit under the Clean Air Act, Plaintiffs NAACP and NAACP Mississippi State Conference…seek to enforce federal law by obtaining civil penalties payable solely to the United States Treasury. In doing so, the NAACP threatens American national, economic, and energy security by seeking to shut off the power supply for artificial-intelligence innovation that supports the Department of War’s military operations. The power to execute federal law, however, belongs to the Executive Branch.

The government said that the CAA grants the US exclusive power over the statute’s enforcement and that the plaintiffs’ claims should thus be dismissed.

The district court ordered the government to comply with the requirements of FRCP 24(c), which requires the moving party to file a pleading setting out the claim or defense for which it seeks intervention.