Nearly six in 10 Americans believe that decisions on whether to prosecute allegations of sexual assault in the U.S. military should be made by an independent group of military prosecutors instead of within the military chain of command, according to a new Washington Post-ABC News poll.

U.S. soldiers pack up to walk down to meet their helicopter following a mission along Pakistan-Afghan border in June 2009. (Nikki Kahn/The Washington Post)

The Pentagon estimates that as many as 26,000 service members were the targets of unwanted sexual contact last year although only 3,374 incidents of sexual assault were reported to top military officials. The rise of such cases has earned special concern from military leaders and lawmakers.

The poll results are a victory for Sen. Kirsten Gillibrand (D-N.Y.), who is pushing to boldly change how the Defense Department handles cases of assault and rape in the ranks by stripping military commanders of any involvement in handling such cases and turning responsibility over to specialized military prosecutors.

Critics charge that the changes could add millions of dollars to the defense budget and radically alter a commander’s responsibilities for good order and morale. But Gillibrand's plan is backed by national veterans groups, victims’ advocates, 17 of the 20 women senators and an impressive bipartisan coalition including Sens. Charles E. Grassley (R-Iowa), Rand Paul (R-Ky.) and Ted Cruz (R-Tex.).

(Update 3:52 p.m.: Senate Majority Leader Harry Reid (D-Nev.) just became the bill's 50th public supporter.)

Sen. Claire McCaskill (D-Mo.) is pushing for different changes that also would help curb assault cases, but stop far short of Gillibrand's proposal. McCaskill's amendment would change military rules of evidence to drop the “good soldier” defense unless a defendant’s military character is directly relevant to the crime they're accused of committing. The plan also would require the secretaries of the Army, Navy and Air Force to review any case in which military prosecutors recommend proceeding and a military commander disagrees. The amendment is likely to pass with bipartisan support.

The Senate is expected to begin debating the Gillibrand and McCaskill proposals in the coming days as part of consideration of the annual defense authorization bill that sets military pay and policy. Gillibrand still lacks the 60 votes necessary to ensure her proposal is added to the bill, while McCaskill's proposal is expected to pass easily.

"We will prevail," McCaskill predicted in an interview Tuesday morning.

McCaskill said that Gillibrand's proposal is impractical and wouldn't properly hold leaders who commanded potential offenders to account.

"If you want more prosecutions and if you want to hold the commanders accountable, I think it's a dramatic mistake to let the commanders to walk away and I think it's a dramatic mistake to say that a lawyer half a continent away is going to make the call and that somehow is going to protect this victim more from retaliation and result in more cases getting to court," she said.

The defense bill already includes several changes to how the Pentagon handles sex assault crimes that supporters consider the most significant changes to Uniformed Code of Military Justice in five decades. The measure would end the statute of limitations on cases of assault or rape; strip military commanders of their ability to overturn jury convictions in assault or rape cases; require that civilians review decisions by commanders to not prosecute certain cases; make it a crime to retaliate against victims who report a sexual assault; and require dishonorable discharge or dismissal for anyone convicted of sexual assault.

But the disagreement between Gillibrand and McCaskill on how much farther to go has divided Senate Democrats and chamber's record 20 women.

In hopes of cooling tempers, Sen. Barbara Mikulski (D-Md.), the longest-serving woman senator, invited her female colleagues to the Senate floor Tuesday to discuss the issue.

"I'm pretty fed up" over the continued scourge of assaults and rapes, Mikulski said. "I'm fed up with lip service and empty promises and zero-tolerance policies and task force after task force after task force."

Support for stripping commanders of responsibility over assault and rape cases crosses all gender, racial, political and ideological divisions. A majority of men (59 percent) and women (59 percent) support the move as do a majority of liberals (69 percent), moderates (65 percent) and a plurality of conservatives (48 percent).

The new Post-ABC poll follows findings from a Post-Pew Research Center poll released in August. In that survey, 45 percent of Americans believed that Congress, and not the military, should make changes to military laws  to cut back on cases of assault and rape. But a majority of respondents also said they have more confidence in military commanders than in lawmakers to address the issue.

Polling analysts Peyton M. Craighill and Scott Clement contributed to this report.