Sen. Mark Kelly is suing the Pentagon. Legal experts say veterans' rights are at stake.

• Senator Mark Kelly sued Defense Secretary Pete Hegseth over the Pentagon's speech crackdown.
• Kelly's lawsuit challenges Pentagon actions targeting retirees' political speech and benefits.
• Legal experts warn the case could impact First Amendment rights for retired US military personnel.

A new lawsuit from a Democratic senator and combat veteran at the heart of a free speech fight seeks to block the Pentagon's intensifying crackdown.

Arizona Sen. Mark Kelly sued Defense Secretary Pete Hegseth on Monday, warning that the Pentagon's effort to punish him "sends a chilling message" to veterans who speak out against the Trump administration.

Hegseth accused Kelly of "seditious" acts after Kelly publicly reminded US service members that they are not required to follow illegal orders. The Pentagon's actions against Kelly have troubling implications for the political speech of millions of veterans, military law experts said.

Hegseth's effort to muzzle a US senator "places other retirees who have spoken up potentially in jeopardy," said Rachel VanLandingham, a professor at Southwestern Law School who is a retired Air Force JAG. "Not knowing whether or not he's going to come after you already has a chilling effect."

Kelly said his lawsuit is about fighting back. The Democratic lawmaker announced the federal lawsuit on Monday. His suit also named the Department of Defense, Navy Secretary John Phelan, and the Navy Department as defendants. Kelly's video urging troops not to follow illegal orders.

Veterans who serve 20 years or more are eligible for a military pension, but those benefits can be revoked or reduced if retirees are found to have violated military law while in uniform. By contrast, Hegseth's move seeks to punish a veteran for his speech long after serving in uniform, an approach one expert on military law called baseless.

Kelly's lawsuit argues that using the military justice system to punish veterans' political speech risks setting a precedent that abuses the First Amendment rights of other retired troops.

Legal basis in question

The lawsuit argues that nothing in the law allows the Pentagon to revisit a retirement determination based on a veteran's speech. Such a move, the filing says, would raise "serious constitutional concerns" and leave retired service members facing a constant threat to their earned benefits.

There's no legal basis for Hegseth's pursuit, VanLandingham said. The defense secretary initially sought to court-martial Kelly, threatening him with the military equivalent of a criminal trial. It later opted for a lesser administrative punishment.

"The process is the punishment," said Frank Rosenblatt, a retired Army JAG and professor at Mississippi College School of Law. "The claim against Kelly had no merit."

"Senator Kelly's speech is not punishable under the UCMJ," the National Institute of Military Justice nonprofit group said in a December statement in reference to the Uniform Code of Military Justice.

The lawsuit seeks to halt actions that could reduce Kelly's military rank and retirement pay and characterizes that effort as "unlawful."

After filing the lawsuit, Kelly requested a temporary restraining order and a preliminary injunction from the federal court, seeking to halt the Pentagon's actions while the case is reviewed on its merits. Both are emergency measures that ask a judge to stop government action before permanent harm occurs.

The federal government has been increasingly pushing cases important to the Trump administration onto a "rocket docket," Rosenblatt said, accelerating litigation toward higher courts. If the judge assigned to the case, US District Judge Richard Leon, issues a ruling the government doesn't like, "this could move very quickly to the DC Circuit and potentially the Supreme Court."

Leon has previously ruled against the military's authority over retirees.

"I am not concluding today that Congress could never authorize the court-martial of some military retirees," Leon wrote in a 2019 memorandum opinion that rejected the government's argument that military jurisdiction over all retirees was necessary to maintain good order and discipline of its active force. The judge noted he had not seen a clear argument for "why the exercise of such jurisdiction over all military retirees is necessary."

In a post on X last week, Hegseth called Kelly's video with five other Democratic lawmakers "reckless and seditious" and said it was "clearly intended to undermine good order and military discipline."

The military justice provisions that Hegseth accused Kelly of violating — Articles 133 and 134 of the Uniform Code of Military Justice — are not explicitly tied to sedition and can cover a wide range of alleged misconduct.

Kelly's lawsuit argues that allowing the executive branch to punish a member of Congress for speech is a threat to the Constitution and erodes congressional oversight of the armed services.

"We are aware of the litigation," a Pentagon spokesperson said Tuesday when asked for comment on the lawsuit. "However, as a matter of policy, the Department does not comment on ongoing litigation." That same day, Hegseth took aim at Kelly's military rank in an X post: "'Captain' Kelly knows exactly what he did, and that he will be held to account."