Congressman Patrick Murphy on Tuesday lost his bid to continue representing the people of Pennsylvania's Eighth Congressional District.

Republican rival Mike Fitzpatrick declared his victory on Tuesday night.

“Today we take America back,” he told a crowd of supporters, the Montgomery News reported.

“I am incredibly humbled,” he added. “I won't let you down.”

Murphy, a military veteran who served in Iraq, led the fight to repeal “Don't Ask, Don't Tell,” the 1993 law that bans gay and bisexual troops from serving openly, when he took over as lead sponsor of the House bill that repealed the ban. The measure was first introduced by Ellen Tauscher before she was tapped by President Obama for a top post in the State Department.

“Tonight the House of Representatives and our country lost a bright, capable young leader,” Aubrey Sarvis, executive director of Servicemembers Legal Defense Network (SLDN), the largest group lobbying for repeal of the policy, said in a statement.

“SLDN will forever remember and be grateful for Patrick's remarkable leadership in the fight to repeal DADT, and I have no doubt Patrick Murphy will be back to serve this nation again. We appreciate his long and extraordinary service to our country.”

The House voted in May to repeal the law that has ended the military careers of over 13,000 gay service members in May, but a September vote on a similar measure was dealt a blow in the Senate by a Republican-led filibuster. SLDN is urging the Senate for a second vote during the chamber's upcoming lame duck session.