Sen. Mark Kelly calls Pentagon investigation into his remarks a move to chill military dissent

Kelly said the Defense Department did not notify him of an investigation because "what they really care about is the public message.”

The Pentagon confirmed late Monday that Hegseth’s office escalated a preliminary review of Kelly to an official command investigation over "serious allegations of misconduct.”

Command investigations are a very common tool used by military officials to look into allegations of wrongdoing that don’t rise to the level of criminal charges. It is far less common for them to be used against a retired service member, much less a sitting member of Congress.

The investigation heightens tensions between the Democratic senator, who was a Navy fighter pilot before becoming an astronaut, and the Trump administration's Pentagon, coming as lawmakers have increased scrutiny of the U.S. military's attacks on boats accused of smuggling drugs in the Caribbean Sea and eastern Pacific Ocean.

Kelly's lawyers push back on the investigation

In a letter this week to the Pentagon, Kelly’s lawyers said that “there is no legitimate basis for any type of proceeding” and that “any such effort would be unconstitutional and an extraordinary abuse of power."

The investigation was ordered after President Donald Trump accused six Democratic lawmakers of sedition “punishable by DEATH" after they appeared in the video urging troops to defy undefined illegal orders.

Hegseth said Kelly is the only one of the lawmakers who formally retired from the military and is still under the Pentagon’s jurisdiction, arguing that “Kelly’s conduct brings discredit upon the armed forces.”

The Defense Department also said it could recall Kelly to active duty for court-martial proceedings.

Legal experts have said Kelly did nothing illegal, the Pentagon was misreading military law and that he could not be prosecuted by the executive branch as a member of Congress.

Former JAG sees no path to a court-martial

Todd Huntley, a retired Navy captain and judge advocate general, said he believes that if Pentagon officials really thought there was something about Kelly’s actions that could lead to a court-martial, the inquiry likely would have been handed over to the Naval Criminal Investigative Service.

“It’s a realization that they are not going to be able to court-martial him and that is what this is setting up is some sort of administrative action,” Huntley said.

He said one of the most likely actions that Kelly could face is a non-punitive letter of censure. It would have almost no actual impact because Kelly is no longer in active service.

The video was released in November by Democrats who served in the military or intelligence community: Kelly, Sen. Elissa Slotkin and Reps. Jason Crow, Chris Deluzio, Maggie Goodlander and Chrissy Houlahan. The lawmakers, who are seen as possible future aspirants for higher office and elevated their political profiles with the video’s wide exposure, spoke “directly to members of the military.”

Kelly told troops that “you can refuse illegal orders,” while other lawmakers in the video said they needed troops to “stand up for our laws ... our Constitution.”

The lawmakers didn’t mention specific circumstances. But their message was released amid the boat strike campaign and Trump's attempts to deploy National Guard troops to American cities.

Democrats and others have called out boat strikes

The issue of illegal orders became even more salient following the revelations of a follow-up strike that killed two survivors clinging to the wreckage of a boat after the first hit, which some legal experts and lawmakers say went against the laws of war.

Trump and several Republican lawmakers have argued that it was justified because the people were trying to overturn the boat and stay in the fight. The administration says the attacks overall are aimed at stemming the flow of narcotics into the country and that the U.S. is engaged in an “armed conflict” with drug cartels.

When it announced its investigation into Kelly, the Pentagon suggested his statements interfered with the “loyalty, morale, or good order and discipline of the armed forces” by citing the federal law that prohibits such actions.

Kelly has rejected the claims by Trump and the Pentagon, saying he upheld his oath to the Constitution.

“They’re trying to shut people up,” he said Tuesday. “But in this case, they picked the wrong guy. So I’m not going to shut up about this.”