On Denver radio, Buck, the leading Republican candidate in the U.S. Senate race in Colorado, compared the "feeling" he had of wanting to be in control of his body during his bout with cancer with the desire of women to make a decision about whether to have an abortion. The difference, he said, is the "life of the unborn child."

Ken Buck

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Appearing on a Denver radio station Monday, Colorado U.S. Senate candidate Ken Buck compared pregnancy with his recent battle with cancer.

“Yes, I am ‘pro-life,’” Buck told KLZ talk-show host Randy Corporon on his Wake Up show. “While I understand a woman wants to be in control of her body—it’s certainly the feeling that I had when I was a cancer patient, I wanted to be in control of the decisions that were made concerning my body—there is another fundamental issue at stake. And that’s the life of the unborn child. And I hold that life dear and precious and believe we have to do everything we can to protect the life of the unborn.”

Buck, who lost a tight race to Sen. Michael Bennet (D-CO) in 2010, is leading a crowded field of Republicans vying to take on pro-choice Democrat Mark Udall in November.

In a December Public Policy Polling survey, Buck was the choice of 45 percent of GOP voters. His closest GOP competitor, state Sen. Randy Baumgardner (R-Hot Sulphur Springs), garnered 8 percent in the poll.

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In 2010, Buck became known for repeatedly discussing his opposition to all abortion, including in cases of rape or incest. In one radio interview, he expressed his opposition to abortion for a girl raped by her teen brother.

Political observers agree that the votes of suburban women cost Buck a U.S. Senate seat in 2010, and Buck’s strong anti-choice positions are seen as a key reason women turned away from him, as well as his statements on other social issues.

Asked to respond to Buck’s radio comments, Karen Middleton, executive director of NARAL Pro-Choice Colorado, told Rewire in an email, “Ken Buck was out of touch with Colorado voters the last time he sought elected office, and he still does not get it. Women must continue to have the fundamental right to have control of her body, and she is the only one who should be making decisions about what happens to her body without interference from politicians or government. Decisions about reproductive health should remain a decision between a woman and her health-care provider, period. Colorado voters have reaffirmed this several times over and will again in 2014.”

In his KLZ interview, Buck also expressed broad opposition to the Obama administration’s compromise position of requiring health insurance companies to include birth control in health plans.

“This administration has ignored those of us who place our faith in the front of our beliefs, and it’s just so sad to think that the government would even want to put itself in the position of forcing a doctor to perform an abortion or issue birth control or do other things that violate that doctor’s conscience or a hospital or an employer require to purchase certain types of insurance,” Buck told KLZ. “It’s short-sighted. It’s, in my opinion, a violation of the First Amendment of the Constitution, of the Bill of Rights. And it’s just sad that we’ve come to this point in our country’s history.”

Under Obamacare, no doctor is required to perform an abortion. The national health law does set minimum standards for health insurance.

Anti-choice Republicans have struggled in recent years in answering abortion-related questions. For example, Rep. Todd Akin’s thoughts about “legitimate rape” sunk his 2010 bid for a Senate seat in Missouri.