The reasons the Senate voted 56–40 against Wisconsin Republican Sen. Ron Johnson’s amendment to reinstate military personnel discharged for refusing the COVID-19 vaccine were made clear during Thursday’s Senate floor debate.

The National Defense Authorization Act for 2023, which was passed last week by the Senate, included a directive to Defense Secretary Lloyd Austin ordering him to revoke his order requiring service members to receive the COVID-19 vaccine. The bill, which will effectively end the vaccine mandate moving forward but does not address the thousands of military members who were discharged for refusing the order to get the vaccine, is anticipated to be signed by President Joe Biden.

“Those who serve in our armed forces are the best of us. Johnson said on the Senate floor that over 8,000 people had their lives ended because they refused to receive the experimental vaccine. He then urged his fellow senators to support the amendment.

With the exception of four Republican senators, Johnson’s amendment would have reinstated service members who were let go solely for refusing the vaccination. It would have also prevented the military from issuing future vaccine mandates without the express consent of Congress, paid back wages, and changed their separation status to an honorable discharge.

Sen. Jack Reed of Rhode Island, a Democrat, opposed the amendment, claiming it would jeopardize future military discipline and order. “What message do we send if we pass this bill?,” Reed said. “What we are telling soldiers is: If you disagree, don’t follow the order and just lobby Congress. … They will restore everything, so orders are just sort of a suggestion. They are not.”

Reed defended Austin’s directive that all military members receive the COVID-19 vaccine. When it was released in August 2021, it had already received FDA approval as a pharmaceutical. It is a binding court order,” Reed stated.

Johnson argued in opposition to Austin’s order, saying that it was not lawful because the executive order demanded that the vaccine have full FDA approval.

Johnson was ostensibly making reference to a lawsuit brought forth in 2004 by service members who objected to a Department of Defense-mandated anthrax vaccination. The Food and Drug Administration did not follow the proper procedures when approving a vaccine, according to U.S. District Judge Emmet G. Sullivan, who also ordered the Pentagon to stop mandating vaccination.

“The United States cannot demand that members of the armed forces also serve as guinea pigs for experimental drugs, absent an informed consent or presidential waiver,” Sullivan wrote in his decision, citing a 1998 law prohibiting a military mandate of a drug not approved for its intended use. Congress passed the law at the time out of concern that Gulf War veterans might have developed the illness known as Gulf War Syndrome after taking drugs that had not been fully approved.

The amendment did not receive the 60 votes it required. Together with Democratic Senators, Republicans Mitt Romney of Utah, Mike Rounds of South Dakota, Bill Cassidy of Louisiana, and Susan Collins of Maine voted against the amendment.

Later, in a statement to the press, Cassidy claimed that “these were direct orders from commanding officers.” “I voted to end the COVID vaccine requirement in the military, but Congress has no business interfering in the chain of command and creating a precedent whereby military personnel can disobey orders,” the voter said.

Johnson and the other nine Republican senators who voted in favor of the amendment wrote to Austin after the vote to urge the Department of Defense to use its own procedures to reinstate discharged service members. The letter gave troop morale as a strong argument in favor of their reinstatement.