Only "dumbasses" in the Tea Party movement question President Barack Obama's citizenship, according to one Republican Senate candidate in Colorado. In response, a spokesperson for GOP rival Jane Norton called Ken Buck a "self-proclaimed tea partier who trashes tea partiers when he thinks no one is looking."

A Colorado Democratic Party worker taped Buck in a parking lot in June without his knowledge; the recording was obtained by 9 News and The Denver Post.

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

Buck later tried to walk back his comments, telling a local TV station, "You know there are times of frustration where I vent and in this case, I vented to the wrong person under the wrong circumstances."

9 News reported:

Asked about the comments on Sunday at a political rally in Adams County, Buck said he wishes he had used different language and that he had not lumped all Tea Party members into one statement, but that he remains frustrated that some people are focusing on birth certificates rather than the country's $13 trillion debt and its $100 trillion in unfunded liabilities.

"The language is inappropriate," he told 9NEWS and The Post. "After 16 months 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.

"It is not the Tea Party movement on the whole. The Tea Party movement gets it. It's the Constitution, it's the debt, it's the other issues, but there are a couple people that are frankly frustrating for all candidates. I mean if you talked to other candidates and they're being honest with you, they'll say I know that. Now, they may not have used my choice words, but they have the same feelings."

Only last week, Buck found himself in the national spotlight for comments that seemed to suggest that voters choose him because he wasn't a woman.

"Why should you vote for me? Because I do not wear high heels," Buck told a crowd at an Alcohol Tobacco and Firearms picnic sponsored by the conservative Independence Institute.

Buck's opponent, Jane Norton, wasted no time in producing an ad spotlighting Buck's remarks about her footwear. It's doubtful she'll produce a new one defending birthers, but Buck's comments still are probably more likely to cost him votes than win any.

However, Politico reports, "The Norton campaign leaped on the remark, 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. He's an alleged fiscal conservative who increased his budget by 40 percent. He's a Tom Tancredo disciple who trashes Tancredo when he thinks the mic is off. Ken says he can appeal to swing voters and beat Michael Bennet, and then trashes the roughly 50 percent of voters who wear high heels. Bottom line: The voters of Colorado can’t trust Ken Buck," said Norton spokeswoman Cinamon Watson.

This video is from KUSA, uploaded by Crooks and Liars July 26, 2010.