Department of State v. AIDS Vaccine Advocacy Coalition strongly suggested that private litigants cannot bring suit under the APA to enforce the Impoundment Control Act. If that (interim) ruling is correct, how can the Impoundment Control Act be enforced?
Justice Kagan, in dissent, explained that the Comptroller General can enforce the law through a lawsuit:
Second, the Act gives the Comptroller General (a legislative officer) a way to sue over presidential impoundments. If he believes the President is unlawfully withholding funds, he is to send a report to Congress saying so. See § 686. And after a specified time, he may bring a civil action under the Act to compel the Executive to obligate the funds at issue. See § 687. According to the Executive's application for a stay, that statutory scheme "impliedly preclude[s]" the plaintiff organizations from bringing an APA suit to similarly enforce appropriations laws. Application 18. That suit, the Executive argues, would "supplant[ ] interbranch negotiations" and "leapfrog[ ] the Comptroller General" if allowed to go forward. Id., at 20
