SAN DIEGO — The Marine Corps has decided to discharge a sergeant for criticizing President Barack Obama on Facebook.

The Corps said today that Sgt. Gary Stein will be given an other-than-honorable discharge for violating Pentagon policy limiting speech of service members.

According to the USA Today, Stein frequently posts derogatory material about President Obama, including superimposing Obama’s face on a movie poster that labels the commander in chief “jackass number one.”

He urged his Facebook followers (including nearly 29,000 on the Armed Forces Tea Party page) to vote against Obama, which directly violates a Defense Department’s rule that bars active-duty members from publishing “partisan political articles, letters or endorsements signed or written by the member that (solicit) votes for or against a partisan political party, candidate or cause.”

In one rant during an online debate over whether U.S. servicemembers could be tried in Afghanistan for burning Qurans, he said, “As an active duty Marine, I say screw Obama and I will not follow any orders from him … I will not salute him … Obama is the … enemy.”

Stein later edited his statement, changing the wording to “unlawful orders.”

That rant violated Article 134 of the Uniform Code of Military Justice, which bars behavior that harms the “good order and discipline in the armed forces”, the newspaper reported.

The San Diego-area Marine has served nearly 10 years in the Marine Corps. He has said he was exercising his free-speech rights.

“I love the Marine Corps, I love my job. I wish it wouldn’t have gone this way. I’m having a hard time seeing how 15 words on Facebook could have ruined my nine-year career,” he told The Associated Press.

The military has had a policy since the Civil War limiting the free speech of service members, including criticism of the commander in chief.

The prosecutor, Marine Capt. John Torresala, said in addition to violating long-established rules that limit the free speech of Marines, Stein repeatedly ignored orders from his superiors to stop the behavior.

Tom Umberg, a former Army colonel and military prosecutor, said Stein likely understood the consequences of ignoring those orders.

“The Marine Corps gave him the opportunity to think about his actions, yet Sgt. Stein continued to undermine the chain of command,” said Umberg, who was not involved in Stein’s case. “I think his purpose was to leave the Marine Corps in a dramatic fashion in order to begin a career in talk radio or what have you.”

The discharge will mean Stein loses his benefits.

Gary Kreep, an attorney for Stein, said he would pursue administrative appeals within the Marine Corps but anticipates the effort will fail. He said he planned to file an amended complaint in federal court.

“As long as he wants to pursue this, we will be supporting him,” said Kreep, who is executive director of the United States Justice Foundation, an advocacy group.