The House on Wednesday sent senators legislation that would end the 1993 law that forbids recruiters from asking about sexual orientation and troops from acknowledging that they are gay.
But supporters in the Senate say there might not be enough time left on the legislative calendar to get the bill through before the end of the session. And failure could mean a lengthy delay for efforts to repeal the "don't ask, don't tell" policy requiring thousands of uniformed gays to hide their sexual identity.
Democratic leaders in the Senate say they are committed to bringing the bill to the floor before Congress adjourns for the year. But they are challenged by opposition from some Republicans and a daunting agenda that includes finishing work on legislation to fund the government and ratifying a nuclear arms treaty with Russia.
Senate Majority Leader Harry Reid, D-Nev., said the House vote proves that an overwhelming majority of Congress wants to repeal the law.
"The time for weeklong negotiations on amendments and requests for days of debate is over," Reid said. "Republican senators who favor repealing this discriminatory policy need to join with us now to stand against those who are trying to run out the clock on this Congress."
The House, in introducing the bill, sought to avoid the complications of combining it with a general defense bill. Sens. Susan Collins, R-Maine, and Joe Lieberman, I-Conn., also promoted a stand-alone bill in the Senate. Supporters say they have the 60 votes for passage if they can get it to the Senate floor, with a handful of Republican senators recently announcing support.
"It is now the Senate's turn to take the final step toward overturning this discriminatory policy," Collins and Lieberman said in a statement. "We are out of excuses."
President Barack Obama reiterated his support for lifting the ban in a statement after the House vote.
"Moving forward with the repeal is not only the right thing to do, it will also give our military the clarity and certainty it deserves," Obama said. "We must ensure that Americans who are willing to risk their lives for their country are treated fairly and equally by their country."
White House press secretary Robert Gibbs said Thursday that Obama has been in touch with Reid regularly on how to move forward. Some activists contend the president could be taking a more public role advocating for repeal.
"There's time to do this if there are those on the other side of the aisle that wish to get this done," Gibbs said.
Failure to overturn "don't ask, don't tell" this year could relegate the issue to the back burner next year when Republicans, who are far less supportive of allowing openly gay individuals to serve in the military, take over the House and gain strength in the Senate.
Pentagon press secretary Geoff Morrell said in a statement after the House vote that Defense Secretary Robert Gates encourages the Senate to lift the ban and thus enable the Defense Department "to carefully and responsibly manage a change in this policy instead of risking an abrupt change resulting from a decision in the courts."
The House passed similar legislation in May as part of a larger defense bill. The measure stalled in the Senate.
Many Republicans, led by Sen. John McCain of Arizona, argue that it would be a mistake for the military to undergo a major cultural change while the nation is fighting two wars.
The issue also has split the military. Gates and other senior military leaders who support lifting the restrictions on gay service point to a recent Pentagon study showing that most people in uniform don't object to serving with gays. But the head of the Marine Corps, Commandant Gen. James Amos, repeated his opposition this week, saying that lifting the ban during wartime could cost lives.
The White House stresses that the change would go into effect only after the president, the secretary of defense and the chairman of the Joint Chiefs of Staff certify that implementation is consistent with military readiness, recruiting and retention and unit cohesion.
More than 13,500 service members have been dismissed under the 1993 law.
The bill is H.R. 2965.