WASHINGTON – After years of opposition from Pentagon leaders, New York Democrat Senator Kirsten Gillibrand appeared to be nearing victory over a fundamental change in the way the military handles sexual assault cases. However, their emphasis on including all serious crimes in the measure for reasons of racial justice now threatens to weaken their support.

Ms. Gillibrand’s push to remove commanders from decisions in prosecuting sexual assault cases had received bipartisan support despite opposition from military leaders. Last month, President Biden and Secretary of Defense Lloyd J. Austin III endorsed a similar change recommended by an independent military body.

But Mr. Austin and some of Mrs. Gillibrand’s strongest allies in Congress on this issue are reluctant to make broader changes to the military justice system. Some lawmakers say they only recently focused on the details of the measure after months of discussion.

“Your bill is much broader than I thought,” said Senator Susan Collins, Republican of Maine and an early proponent of Ms. Gillibrand’s move. “I believe she has made a compelling case for sexual assault and related allegations to be removed from the chain of command.”

But Ms. Collins said she didn’t think there was any justification for removing other alleged crimes from the military justice system.

Ms. Gillibrand’s bill would overturn the decision to prosecute serious crimes such as sexual assault and other crimes such as murder from military commanders to military prosecutors. The Pentagon panel proposed a more limited change: that a special victim unit should be set up within the military for cases of sexual assault and some other crimes.

But Ms. Gillibrand argues that this would create an unequal system and has said that her proposal would also help fight racial injustice.

A bill that would cover most crimes is “necessary,” she said in the Senate on Tuesday, “because the current military justice system simply does not provide justice, especially for soldiers of color.”

This tactic has helped attract other voices to their cause.

“Racial and gender bias in the military has resulted in inadequate prosecution of sexual assault cases and excessive prosecution of black and brown officers,” said Anthony Brown, Rep. Anthony Brown, Democrat of Maryland, a veteran and former Army Attorney General an interview this week.

While there have been differences in prosecution in the military over time, he said, “I think after the tragic murder of George Floyd, it really got a lot of us to say, ‘Hey, this is a real opportunity here, this one Fix inequalities and differences. ‘“

Studies over the years have identified racial differences in the military justice system, including the way in which discipline is exercised.

The tensions over Ms. Gillibrand’s move and the closer changes recommended by the Military Commission are potentially difficult terrain for Mr. Austin. He said strengthening the fight against sexual assault, racism and extremism in the ranks is a top priority.

Many military leaders who oppose changes in sexual assault cases may also oppose the loss of other prosecutorial powers. But focusing on other crimes could also alienate some of Ms. Gillibrand’s supporters – many of whom were brought back after years of courting.

“My inclination now is to commit sexual assault,” said Senator Angus King, Maine Independent, after previously saying he would register with Ms. Gillibrand. “That has been the goal of our work for eight years.”

Among the 70 or so senators from both parties who joined this spring, Ms. Gillibrand still seems to enjoy support. Senator Ted Cruz, a Republican from Texas, has been with their side for years, while some Democrats, like Senator Tim Kaine of Virginia, recently joined their efforts.

“There are many reasons to professionalize crime-dealing,” said Kaine, who previously worked as a lawyer. “Kirsten has a bright line that was maybe a little different from the one she drew earlier. But it’s a line that makes sense for us lawyers. “

Republican Senator Josh Hawley from Missouri agreed. “As a lawyer and former prosecutor, I think there is some value in having continuity and saying that every crime is handled the same way no matter what it is. I like that as a former prosecutor and I like it as a defense attorney. For me it’s a plus. “

Both men said they support the bill in writing but welcome further debate on the proposed changes that would require a Congressional resolution.

Senator Jack Reed, Democrat of Rhode Island and chairman of the Senate Armed Forces Committee, now supports changing the prosecution for sexual assault after years of opposition. But he is a leading voice against extending this trial to other crimes.

Data on racial differences is mixed and sometimes inconclusive, in large part due to the military’s lack of consistent data on race and the justice system, several reports say.

A recent report by the Government Accountability Office found that black and Hispanic military personnel were more likely than whites to be tried in a military trial, but that race “was not a statistically significant factor in conviction.”

A report by the Air Force Inspector General last year found that black service members were 1.64 times more likely to be suspicious in Office of Special Investigations criminal cases, but said that “identifying racial differences does not automatically imply racial bias or racism available”. . “