At center, Defense Secretary Gates. (Creative Commons)

Defense Secretary Robert Gates and other top U.S. military officials repeated their backing of a bill that would lift the ban on gays openly serving in the armed forces at a Senate hearing Thursday morning, though it remains to seen if moderate Republicans will join with them.

"Our people sacrifice a lot for their country, including their lives. None of them should have to sacrifice their integrity as well," said Chairman of the Joint Chiefs of Staff Mike Mullen before the Senate Armed Services Committee.

A Pentagon report released Tuesday about the effects of a repeal of "Don't Ask, Don't Tell," the nearly two-decade-old policy that bars homosexuals from openly serving, showed widespread support from the military.

The legislation has already passed the House of Representatives. If all 58 Senate Democrats support the measure, which isn't a lock, they would need need at least two Republicans to join them to prevent a filibuster of the measure.

As of Wednesday, moderate Republicans weren't giving any clues as to how they would vote. Republican leaders have vowed to block any non-spending or tax cuts-related bills, hoping to crush changes in social policies such as "Don't Ask, Don't Tell" and the DREAM Act.

One of California's senators, Barbara Boxer, wrote an op-ed in Thursday's San Francisco Chronicle about the proposed repeal, saying, "We have a chance to move our country forward toward full equality - and we must not waste it."

If the Senate fails to pass a repeal before the end of the year, there's still hope for gay rights supporters. A federal judge ruled in September that the ban on gays was unconstitutional. The Obama administration appealed the ruling and a hearing is expected to be held in early 2011. Presumably, the appeal could be dropped if the Senate can't pass the legislation. After the initial ruling by Judge Virginia Phillips, there was an eight-day period during which the ban was technically not in place.

Reach executive producer Paresh Dave here. Follow him on Twitter: @peard33.