Sen. Kirsten Gillibrand will make another big push on her amendment to take major military crimes (including sexual assault) outside the military chain of command on Monday. She has the backing of at least 47 senators, but the Democratic Party doesn't agree on the amendment. Competing proposals, especially one from Sen. Claire McCaskill, have kept the Senate from agreeing on a plan to send to the House. Even Defense Secretary Chuck Hagel can't explain how to reduce the number of sexual assaults in the military (an estimated 26,000 in 2011): 

"Because it is the culture. It is the institution. It’s the people within that institution that have to fix the problem, and that’s the culture. The people are the culture. So I don’t know how you disconnect that from the accountability of command."

Hagel produced that bit of word salad in June when speaking out against Gillibrand's amendment

McCaskill's amendment doesn't take sexual assault cases outside the military chain of command, but it does stop commanders from overturning jury verdicts and mandate that anyone convicted of sexual assault be dishonorably discharged or dismissed. Her amendment has the support of Armed Services Committee Chair Carl Levin and the Pentagon. 

Though Gillibrand and McCaskill have both championed women throughout their careers, their disagreement over the chain-of-command issue has pitted the two against each other. McCaskill has already faced backlash from some groups who see her as anti-victim, a charge she deems "unfair."

"The reason this issue is so hard is because on one side is a very simple narrative, this is victim versus commanders and you should be for the victims," McCaskill told ABC News. "On the other side, it's much more complex, and I'm guided by practical experience handling these cases and a pretty intimate knowledge of the Uniform Code of Military Justice and how it actually works ..."

McCaskill is the fourth-ranking Democrat on the Armed Services Committee. 

Gillibrand, for her part, isn't looking to compromise. "We’re going to stick to the original plan because it’s a better bill," she said in an appearance on The Week on Sunday. Conservative Sens. Ted Cruz and Rand Paul support Gillibrand's amendment. So do 16 of the Senate's 20 women. Gillibrand thinks it's important to take cases outside the chain of command because vicims "didn't trust the chain of command. ... they feared or had witnessed retaliation." 

"It is not personal for me," she told National Journal last week. "Senator McCaskill has spent months on this issue. She cares deeply. We just disagree on this one issue. And I'm fighting for it because I think it will make the difference ... in more reporting, more cases going to trial, and more convictions."