Claire McCaskill. (Photo: Project On Government Oversight / Flickr)Washington – The Senate on Thursday rejected legislation that would have stripped military commanders of the power to prosecute sexual assaults and other major crimes.

The bill, proposed by Sen. Kirsten Gillibrand, D-N.Y., had the support of 55 of the chamber’s 100 members, including 10 Republicans. But it was blocked by fellow Democrat Claire McCaskill of Missouri and other lawmakers from both sides of the aisle, who used procedural tactics to prevent an up-or-down vote on the measure.

The Senate instead moved unanimously toward approval of an alternative bill championed by McCaskill that would preserve commanders’ authority to convene courts-martial but give victims a formal say in whether their cases go before military or civilian courts. That version awaits final passage next week.

“I know this has been tough for everyone,” said McCaskill, a former prosecutor, as two hours of tense debate drew to a close Thursday. “But I stand here with years of experience of holding hands and crying with victims, knowing that what we have done is the right thing for victims and the right thing for our military.”

The hard-fought policy battle between two influential female senators came down to just a handful of votes, with Gillibrand’s bill falling five short of the necessary 60-vote threshold.

Although she lost this round to a technicality, Gillibrand demonstrated she has the support she needs to keep her vision for change alive, said Eugene R. Fidell, who teaches military justice at Yale Law School.

“It’s outrageous that a member of the same party would basically threaten a filibuster,” Fidell said of McCaskill.

“I think Senator Gillibrand has the high moral ground, and I believe she will have the high political ground before you know it,” he said. “In practical terms, this bill will live to fight another day.”

Gillibrand and her allies argued during debate Thursday that the only way to restore trust in the military justice system was to allow independent prosecutors – not commanders – to decide whether a case should go to trial.

“It is like being raped by your brother and having your father decide the case,” Gillibrand said. “That is the perception of the victims.”

McCaskill and other opponents of Gillibrand’s bill argued that taking commanders out of the equation would let them off the hook for their troops’ behavior, erode unit cohesion and expose victims to retaliation.

If you undermine a commander’s authority, his unit “will fall apart,” said Sen. Lindsey Graham, R-S.C., a Reserve Air Force legal officer.

“The commander of that unit is the person we give ultimate authority to make life or death decisions for that unit,” Graham said. “The worst thing that can happen for a unit is for a commander to say, ‘This (sexual assault) is no longer my problem.’”

Last year, Gillibrand and McCaskill worked together to pass major changes in an effort to reduce sexual assaults in the military.

Those changes, which already are being implemented as part of the annual defense bill, prevent commanders from overturning jury convictions, require civilian review of any case a commander decides not to prosecute, mandate dishonorable discharge for those convicted of sexual assault and make retaliation against victims a crime.

Among supporters of Gillibrand’s bill were Democrats Barbara Boxer and Dianne Feinstein of California and Republicans Ted Cruz of Texas and Rand Paul of Kentucky.

Boxer argued passionately for Gillibrand’s bill, criticizing the procedural move to block the legislation, called a filibuster, as she stood in front of a huge sign with a red line through the words “Filibuster Justice.”

“I know that Senator McCaskill is trying to fix these problems around the edges, fine, but let’s get to the heart of the matter,” Boxer said. “ . . . If you have problems with the bill, vote against the bill, but don’t filibuster justice.”

McCaskill voted against allowing Gillibrand’s bill to move forward. Her spokesman, John LaBombard, said it was important to note that both bills were subject to a 60-vote threshold. “Everything requires 60 these days,” he said.

McCaskill does not oppose the filibuster, he added.

“She’s recognized Republican abuse and voted to restrict its use, but she supports use of the filibuster against deeply controversial bills,” LaBombard said.