"Birtherism" reared its head in the waning hours of the Western Republican Leadership Conference when a participant asked Sen. Mike LeeMichael (Mike) Shumway LeeTrump plan to claw back billion in spending in peril Senate passes 6B defense bill This week: House GOP caught in immigration limbo MORE (R-Utah) and Rep. David SchweikertDavid SchweikertMembers of Congress demand new federal gender pay audit Republican candidate favored in Arizona special House election Ryan leaves legacy of tax cuts and deficits 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 John Trump20 weeks out from midterms, Dems and GOP brace for surprises Sessions responds to Nazi comparisons: 'They were keeping the Jews from leaving' Kim Jong Un to visit Beijing this week 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.