In American politics, the Clean Water Act is almost sacrosanct. Despite years of litigation demonstrating the act’s defects and significant constitutional questions, it remains virtually unchanged by Congress, primarily because even rational efforts to reform environmental regulations are inevitably painted by their opponents as attempts to poison the environment.

The Supreme Court is not bound by such political constraints. This week, Justice Kennedy filed a concurring opinion joined by Justices Alito and Thomas in Hawkes v. Army Corps of Engineers implying that portions of the CWA might be found unconstitutional, unless Congress adds some much needed clarity to the law. While this is not the first time that a Supreme Court justice has questioned the constitutionality of the CWA — Justice Alito made similar arguments in Sackett v. EPA — it is the first time that three members of the Court have simultaneously expressed willingness to put the CWA on trial. The concurrence is particularly noteworthy because it was drafted by Justice Kennedy — a pivotal swing vote who authored the definitive opinion on the scope of CWA just ten years ago in Rapanos v. United States.