More than a dozen legal groups bankrolled by tens of millions in dark money tied to a conservative judicial mastermind are urging the Supreme Court to kneecap federal agencies’ ability to protect consumers and impose vital fees on companies. If the groups are successful, the ruling on a little-known regulation could further constrain federal agencies’ power and give corporations free rein to pollute the environment and swindle the average consumer.

On Wednesday, the justices heard arguments on Federal Communications Commission v. Consumers’ Research, which could decide whether federal agencies are still allowed to undertake certain essential government tasks, such as rulemaking and imposing necessary fees on companies and consumers. The defendant in the case, Consumers’ Research, and thirteen conservative groups supporting its efforts are all in part bankrolled by a nonprofit connected to Leonard Leo, President Donald Trump’s former judicial adviser, who played a key role in constructing the Supreme Court’s conservative majority and maintains close ties to two of the justices.

Leo’s ultimate goal includes plans to “crush liberal dominance” and help establish more conservative values and judges in the federal judiciary. His connections to Justices Clarence Thomas and Samuel Alito has prompted ethics watchdog group Accountable.US to call for their recusal from the case.