Updated

A Republican Senate candidate in Colorado, who has positioned himself as the Tea Party favorite, could be in trouble after calling activists who harp on the issue of President Obama's birth certificate "dumbasses."

The Denver Post obtained the audio recording that it says shows Ken Buck complaining about fringe activists known commonly as birthers.

"Will you tell those dumbasses at the Tea Party to stop asking questions about birth certificates while I'm on the camera?" the man identified as Buck said at a June event. "What am I supposed to do?"

When asked about the comment by Fox News, Buck acknowledged he could have been more "artful."

"It was a few people in a few instances that focus so much on the birther issue that it takes away from my overall point that we need to talk about the $13 trillion of national debt, and the nationalized health care bill that has been passed, and that's where I was expressing my frustration," he said. "I could have used more artful terminology, but the frustration remains the same. We need to get back to the issues."

Though some Tea Party members espouse the widely debunked theory that Obama was not born in Hawaii, Tea Party leaders have tried to muffle that segment of the conservative movement in favor of focusing on limited government platforms.

The birther comment alone might not hurt Buck, but it comes on top of two other gaffes. He once was recorded saying he couldn't believe former Rep. Tom Tancredo "opens his mouth." At another event he was asked why voters should choose him. His response: "Because I do not wear high heels." His primary opponent is former Lt. Gov. Jane Norton.

Norton spokeswoman Cinamon Watson said the remarks show Buck cannot be trusted.

"Ken Buck is two steps short of a fraud. He's a self-proclaimed Tea Partier who trashes Tea Partiers when he thinks no one is looking," she said in a written statement.