A forthcoming Pentagon study on the impact of repealing "don't ask, don't tell" will reportedly show that most service members wouldn't care if they had to live and work alongside openly gay and lesbian peers.
Two sources familiar with the closely-held draft report told the Post there's little evidence that changing the law would significantly hurt unit cohesion or combat readiness.
But 40 percent of Marines expressed concern over repeal, according to the sources, a finding that is likely to embolden political opponents of changing the law.
Marine Corps Commandant Gen. James Amos has been a fervent supporter of "don't ask don't tell," telling a Senate panel at his confirmation hearing in September that repeal could create "disruption to cohesion" and pose a "distraction" to Marines engaged in combat operations.
Amos was chastised by his boss, Chairman of the Joint Chiefs Adm. Mike Mullen just last week, for making public statements on the policy after being instructed to make recommendations privately to the chain of command.
But Amos has said he feels strongly that ending the policy would uniquely impact the Corps -- the military service branch that most commonly bunks troops together instead of in private quarters.
"Unlike the other services, we have consciously, for decades now, billeted by twos," said Amos' predecessor, former Marine Corps commandant Gen. James Conway, who also opposes repeal. "So if the law changes, we start out with a problem in terms of how to address that."
Republicans, including Sen. John McCain, have been keenly sensitive to concerns raised by Conway, Amos and other service chiefs, vehemently opposing a legislative change to the ban on gay troops during a time of war, or at least prior to completion of the survey to allow troops to share their views.
But with the eagerly-anticipated study now nearing release and its findings shared with members of Congress, advocates for repeal hope the political dynamic will change.
Senate Majority Leader Harry Reid has promised another vote during the lame duck session which begins next week.
"It's clear a majority of Americans in both the military and civilian spheres agree that 'don't ask, don't tell' is outdated and should go," said Aubrey Sarvis, an Army veteran and executive director of the Service Members Legal Defense Network. "Congress needs to catch up and the Senate should immediately act on repeal when it returns to Washington next week."
"No one should be surprised if a vocal minority, for a short window, might object, as a minority did when segregation in the ranks ended and women were admitted to the service academies," she said. "In the military you get over your objections or you get out."
The early media reports of the study's findings suggest there will be ample fodder for both sides of the repeal debate, if and when the Senate reconsiders the measure.
A final copy of the Pentagon study is due on Defense Secretary Robert Gates' desk Dec. 1. It's unclear when it will be publicly released.
The military surveyed 400,000 active-duty and reserve troops and separately surveyed 150,000 military spouses, probing anticipated reactions to a range of issues including showering or bunking with openly gay or lesbian service members and attending social functions which same-sex couples might also attend.
The review was designed to examine both the potential consequences of allowing gay troops to serve openly as well as identify challenges for integrating openly gay troops into the armed forces under existing laws.
President Obama, Adm. Mullen, and Gates have all called for a repeal of the policy.
A recent CNN/Opinion Research poll found that 78 percent of the public supports allowing openly gay people to serve in the military, with one in five opposed.
However Congress proceeds, Gen. Amos has pledged to abide by the law.
"We are the most disciplined service of all the ones that you have," he told lawmakers earlier this year. "We follow orders. "