Mark Kelly is a sitting U.S. Senator from Arizona and a retired captain in the U.S. Navy. In late 2025, Senator Kelly made several public statements criticizing the Trump Administration’s military policy. For instance, he appeared in a video addressed to service members, in which he was joined by other federal legislators, saying “Our laws are clear. You can refuse illegal orders.”

The Department of Defense (“DOD”) announced shortly thereafter that he would be placed under review for “serious allegations of misconduct.” The DOD informed Senator Kelly that he was potentially subject to reduction of retirement pay, reduction in rank, and recall into active-duty service. Furthermore, Secretary of Defense Pete Hegseth stated that Senator Kelly could be subject to “criminal prosecution” for his comments.

On January 12, 2026, Senator Kelly filed suit alleging a violation of his First Amendment rights. He also asked the district court for a preliminary injunction that would halt the DOD’s retirement review. The district court found that Senator Kelly was likely to succeed on the merits of his First Amendment claim and granted the injunction. The government appealed. Cato has filed an amicus brief in support of Senator Kelly.

Cato’s brief argues that the government’s position — that it has the power to revoke Senator Kelly’s benefits over his political comments — violates the doctrine of unconstitutional conditions. That doctrine prevents the government from punishing speech by denying or revoking government benefits. In this case, the government attempted to frame its speech restrictions as a part of an “exchange” between retirees and the military. This characterization obscures a fundamental constitutional problem: in effect, the government is attempting to impose a monetary penalty on the exercise of First Amendment rights. If the government prevails, it will do more than just censor Senator Kelly. It will force millions of retired service members, many of whom live under financial strain, to choose between their benefits and their First Amendment rights.

Cato’s brief also argues that Senator Kelly’s status as retiree cannot result in a blanket forfeiture of his First Amendment protections. The government argues that it should be allowed to determine what speech receives protection. However, as a general matter, courts are certainly not required to defer to the executive branch on such constitutional questions. Rather, when the Court has recognized status-based speech restrictions, it has provided a workable, replicable standard. Deference to the executive mangles and diminishes the role of the judiciary in our constitutional system of checks and balances. The Secretary of Defense cannot be the lone arbiter of whether Senator Kelly’s — or any retiree’s — speech receives First Amendment protection.