Updated

Opponents of the "don't ask, don't tell" policy against gays serving in the military are hoping for another major legal victory as a federal trial begins Monday over whether to reinstate a lesbian flight nurse discharged from the Air Force Reserve.

The trial comes just days after a federal judge in California declared "don't ask, don't tell" an unconstitutional violation of the due process and free speech rights of gays and lesbians. While the ruling does not affect the legal issues in the case of former Maj. Margaret Witt, gay rights activists believe a victory — and her reinstatement — could help build momentum for repealing the policy.

"There's already political momentum to do something to repeal this unfair statute," said Aaron Caplan, a professor at Loyola Law School in Los Angeles who is on Witt's legal team. "Judicial opinions from multiple jurisdictions saying there's a constitutional problem with this ought to encourage Congress to act more swiftly."

Witt was a member of a squadron based at McChord Air Force Base near Tacoma when she was suspended in 2004 and honorably discharged. She challenged the constitutionality of her dismissal, and a federal appeals court panel ruled in 2008 that the military could not discharge service members for being gay unless it proved that the firing furthered military readiness.

The case was sent back to U.S. District Court in Tacoma for Judge Robert Leighton to determine whether Witt's firing met that standard. Several of Witt's former colleagues are expected to testify that she was an excellent nurse, and it was her dismissal — not her sexual orientation — that caused morale problems in the unit.

Justice Department lawyers representing the Air Force note that the case has put them in the position of defending a law neither the president nor the department itself believes is good policy. Defense Secretary Robert Gates also favors repealing the 1993 law, which prohibits the military from asking about the sexual orientation of service members but allows the discharge of those who acknowledge being gay or are discovered to be engaging in homosexual activity.

Government lawyers nevertheless insist Witt's firing was justified — and that the panel of the 9th U.S. Circuit Court of Appeals did not know the extent of her conduct when it sided with her in 2008. That conduct included a long-term relationship with a civilian woman, an affair with a woman who was married at the time and two earlier relationships with fellow servicewomen, Witt acknowledged in a deposition in May.

It was a 2004 e-mail from the husband of the married woman to the Air Force chief of staff, Gen. John Jumper, that prompted the investigation into Witt's sexuality.

Witt acknowledged the extramarital affair was not consistent with good "officership." She also said she told two members of her unit about her orientation — forcing them to choose between loyalty to Witt and Air Force policy, the Air Force argues.

For those reasons, it says, Witt's firing did further military goals, even if 19 current and former members of Witt's unit have submitted declarations saying they had no problem serving with her.

"Those co-workers are not military commanders, and the military cannot operate by a unit referendum process in which disciplinary policies and outcomes are determined by the individual opinions of a few unit members," Justice Department attorney Peter J. Phipps wrote in a court filing.

The Air Force also says Witt can't be reinstated because she no longer meets Air Force nursing requirements, something Witt's attorneys dispute.

Witt's attorneys, led by the American Civil Liberties Union of Washington, say that it is the Air Force's burden to prove that her reinstatement would be a detriment to unit cohesion. And, ACLU attorney Sarah Dunne says, the Air Force has provided no such evidence.

Gen. Charles E. Stenner Jr., an expert witness for the government, said in a deposition that he didn't know if Witt's reinstatement would negatively affect military functions, and the current commander of Witt's unit, Col. Janette Moore-Harbert, acknowledged having no evidence to that effect.

The trial is expected to last seven days. Meanwhile, the Senate could take up a defense bill passed by the House that includes a provision to end "don't ask, don't tell."