DENVER
07/26/2010 10:01 am ET | Updated May 25, 2011

Ken Buck: Tea Partiers Questioning Obama's Citizenship Are 'Dumbasses'

A Tea Party-backed Senate candidate in Colorado was caught on tape Friday referring to 'birthers' who question President Obama's citizenship as "dumbasses." Republican Ken Buck, who has harnessed Tea Party support to become the front-runner for the GOP Senate nomination, made the comment unsolicited to a Democratic staffer after an event in Pueblo, Colorado.

He was unaware that the conversation was being recorded.

"Will you tell those dumbasses at the Tea Party to stop asking questions about birth certificates while I'm on the camera," Buck said to the staffer. "God, what am I supposed to do?"

Buck told the Denver Post he regretted the language he used, but maintained that he has become frustrated by so-called 'birthers' who question the validity of Obama's birth certificate.

Buck said he considers 'birthers' to be a distraction.

"After 16 months of being on the campaign trail, I was tired and frustrated that I can't get that message through that we are going to go off a cliff if we don't start dealing with this debt," Buck said.

Buck's Republican opponent, Jane Norton, was quick to capitalize on the comments, calling Buck, "two steps short of a fraud."

"He's a self-proclaimed Tea Partier who trashes tea partiers when he thinks no one is looking," a Norton spokesman said in a statement.

This is the second time in a week that Buck has been caught on camera making controversial statements. Last week, video surfaced of Buck jokingly telling a questioner at an event that they should vote for him because "he doesn't wear high heels."

LISTEN: ('Birther' comments start at 3:15)