"Birtherism" reared its head in the waning hours of the Western Republican Leadership Conference when a participant asked Sen. Mike LeeMike LeeWill Trump back women’s museum? Overnight Cybersecurity: Lawmakers pushing for vote to delay warrant rule changes Coons to call for voice vote to halt changes to hacking rule MORE (R-Utah) and Rep. David SchweikertDavid SchweikertThe Hill's 12:30 Report Former GOP congressman lobbying for electric cars Senate races heating up MORE (R-Ariz.) why they weren't pushing to impeach Obama for what he said were Obama's falsified citizenship documents.

There is no evidence that Obama has falsified documents or committed any impeachable offenses, but the issue has continued to follow Obama three years after it emerged during the 2008 election.

"We need to win 2012," Schweikert said, telling the questioner that although he could be right, it wasn't worth alienating independents and conservative Democrats who might vote Republican, but who he said are turned off by the focus on Obama's citizenship. "You may be the one where you tell a great story. But understand, you are giving up the 2102 election."

Lee said Congress was the wrong place to turn to enforce citizenship requirements, because state governments run elections. He said he wasn't sure there was any evidence that Obama had falsified documents or committed an impeachable offense.

"I think the birther thing is a loser. We're going to impeach Obama, but we're going to do it in the voting booth," another audience member chimed in, to the applause of Lee and Schweikert.

During the 2008 campaign, Obama released his short-form certificate, certified by his home state of Hawaii. Then in April 2011, he released the long-form version after Donald TrumpDonald TrumpRyan: Trump noticed his hotel from my balcony Ryan: Obamacare repeal is first priority under Trump Ryan: Trump understands there's a Constitution MORE continually accused him of not being an American citizen. But critics have continued to suggest that Obama's documents were forged.

Obama supporters have argued that ruminations about Obama not being an American or eligible to serve as president are grounded in racism, an accusation that birthers reject.