Two competing proposals on combating sexual assault in the military could cause further headaches for Democratic leaders, as lawmakers debate how best to manage what has become an epidemic culture of misconduct in the armed services.

The fight, which does not break cleanly on party or gender lines, could get more complicated as Congress inches closer to full debate of this year’s defense authorization bill.

On Thursday, Sen. Claire McCaskill, D-Mo., held a news conference with Republican Kelly Ayotte of New Hampshire and Democrat Jon Tester of Montana, to advocate for the proposal approved by the Senate Armed Services Committee last month. Flanked by retired female servicemembers, the senators argued that removing the chain of command from prosecuting misconduct could lead to fewer consequences for assailants in cases prosecutors find too difficult to try.

On the other side, Sen. Kirsten Gillibrand, D-N.Y., has pushed legislation that would remove the command structure from prosecutions completely, and her plan has picked up significant support from members of both parties.

“Sen. Gillibrand would be the first to tell you that our bill is not the status quo. It is aggressive and [makes] meaningful changes,” McCaskill said Thursday. “I’ve had to discipline prosecutors who were turning down cases because they were worried about their win-loss record. Prosecutors like to win, and a lot of these cases they think are ‘losers.’ We see instances where time after time prosecutors say ‘no’ and commanders say ‘yes.’

“Doing this is not the magic bullet,” McCaskill said of removing prosecutions from the chain of command. “Common sense will tell you if you’ve been victimized and you go back in the unit, do you think it’s more likely to get retaliation if a bunch of outside lawyers said to move forward or if a commander said to go forward. A level of protection comes to the victim because the commander has said we’re going to get to the bottom of this.”

In June, the Senate Armed Services Committee was divided over how to proceed, with a fair number of senators backing Gillibrand but a majority supporting the language put forward by Chairman Carl Levin, D-Mich.

McCaskill and Ayotte defended Levin’s reforms Thursday. Gillibrand’s measure is opposed by the military’s top brass, including Secretary of Defense Chuck Hagel.

The Department of Defense estimated that 26,000 incidents of sexual misconduct occurred in 2012. The staggering, though vague, numbers — the DOD does not differentiate between violent attacks and sexual harassment in these figures — have been compounded in recent months by stories of some officers in charge of sexual-assault prevention task forces being accused or charged with sexual assault themselves.

There is significant overlap between the Gillibrand bill and the measure approved by the Armed Services Committee. For example, both bills would strip commanders of the authority to dismiss sexual-assault convictions. They also would criminalize retaliation against victims who report assault, mandate dishonorable discharges or dismissals of assailants, rescind the statue of limitations in assault cases, eliminate “military character” as a consideration for disposition and provide guidance for moving the accused assailant from a unit. The committee-approved bill would allow victims to report attacks inside or outside the chain of command, but commanders would remain involved in the trying of the potential case. Many victims groups, however, have come out in support of Gillibrand’s bill.

The dramatic nature of the debate, and on a “women’s issue” that typically unites Democrats, creates a unique problem for Democratic leaders, who are also divided on which legislative recourse they prefer. Sen. Charles E. Schumer, D-N.Y., for example, is a co-sponsor of Gillibrand’s bill, while Richard J. Durbin of Illinois, the Senate’s No. 2 Democrat and chairman of the Appropriations Subcommittee on Defense, said Thursday he is still undecided.

“I am looking at both of them,” Durbin said, adding that he hoped Gillibrand would get a full-Senate vote during defense authorization act consideration no matter what.

“If it moves in the Gillibrand direction, there will be a need for investment in the judge advocate general’s corps because there will be more requests going to them rather than through the chain of command,” he continued, when asked what his responsibility might be as the top appropriator of defense funding.

When asked about McCaskill’s concerns — that prosecutors could turn down difficult cases commanders still could consider — Durbin said such thinking was part of his personal decision process on the issue.

“That’s part of it and that’s a good point. Sen. McCaskill has a unique perspective as a former prosecutor as to what is actionable, what you can bring a criminal case on. … That’s one of the elements I’m considering in terms of my position,” Durbin said.