The Army National Guard has fired Lieutenant Dan Choi for his membership in a West Point graduate group that lobbies against the military's ban on open gay service.

Choi appeared in March on MSNBC's Rachel Maddow Show to promote the newly formed group, Knights Out. During his appearance, Choi agreed he could be fired for his participation in the group.

“Is there a possibility that you could lose your job? That you could be at risk for getting kicked out of the service for doing this?” Maddow asked.

“Absolutely,” Choi replied.

The group supports the thousands of LGBT soldiers currently serving in the armed forces and educates military leaders on the “importance of accepting and honoring the sacrifices and selfless service of their LGBT soldiers and officers,” according to a press release.

The group also lobbies for repeal of “don't ask, don't tell” – the 1993, President Bill Clinton-approved law that prescribes discharge as the remedy for gay service members who do not remain quiet about their sexuality or do not remain celibate.

Wednesday, Choi, an Iraq War veteran and Arab linguist, received his discharge notification from the Army National Guard.

“This is to inform you that sufficient basis exists to initiate action for withdrawal of federal recognition in the Army National Guard for moral or professional dereliction. … Specifically, you admitted publicly that you are a homosexual, which constitutes homosexual conduct. … Your actions negatively affected the good order and discipline of the New York Army National Guard,” the letter states.

Thursday, about 25 people protested the firing near an U.S. Army recruitment office in Irvine, California, reports the Orange County Register.

“To throw out someone with all that knowledge and training is a huge disservice,” Archer Altstaetter, whose sister, a lesbian, was discharged from the Air Force, told the paper. “It's just not conscionable.”

Choi was fired, ironically, for speaking out against “don't ask, don't tell.”

“One of the harder things was coming back from Iraq,” Choi told Maddow in March. “Being an Iraq combat veteran, an Arabic linguist, a West Point graduate, I come back to America as a second class citizen who is forced to lie because of this rule – because of this law – and because Congress has not yet overturned this. And we're saying, once and for all, it needs to be repealed.”