Congressman Cory Gardner, who has been hammered for his position on social issues ever since he jumped into the U.S. Senate race, dropped a political bombshell Friday with his revelation that he was wrong to have supported previous personhood efforts.

He said that after learning more about the measures, which would have had the impact of outlawing abortion, he realized the proposals also could ban certain forms of contraception, a prohibition he does not support.

“This was a bad idea driven by good intentions,” he told The Denver Post. “I was not right. I can’t support personhood now. I can’t support personhood going forward. To do it again would be a mistake.”

Gardner, a Yuma Republican who has represented the conservative 4th Congressional District since 2011, late last month jumped in the U.S. Senate race to try to unseat Democrat Mark Udall.

He did not say when he changed his mind on personhood, but said he began examining it more closely after voters rejected it by a 3-to-1 margin in 2010.

“The fact that it restricts contraception, it was not the right position,” Gardner said. “I’ve learned to listen. I don’t get everything right the first time. There are far too many politicians out there who take the wrong position and stick with it and never admit that they should do something different.”

Udall’s campaign spokesman, Chris Harris, pointed out that Gardner the last two years co-sponsored the Life Begins at Conception Act, which defines a human being as “a member of the species homo sapiens” at the moment of fertilization. He said it was basically a federal version of the personhood amendment, a position with which Gardner’s campaign disagrees.

“Coloradans will see through this cheap election-year stunt,” Harris said. “Gardner is showing a profound lack of respect for Colorado voters. Coloradans want a senator who always promotes and protects women’s health, not one who simply pretends to during election years.”

Gardner conceded that with his new position on personhood, he might be accused of flip-flopping simply to make himself more palatable to statewide voters.

But he pointed to Udall, who in a 2012 opinion piece in Politico explained how his views had changed to the point where he supported marriage for same-sex couples.

“It was perhaps best said by Mark Udall, who said a good-faith re-examination of a position you’ve held in the past should be seen as a virtue, not a vice,” Gardner said.

After Gardner entered the Senate race, liberal groups distributed a video of a 2010 congressional debate featuring Gardner, then a state lawmaker, and others vying for the GOP nomination for Congress.

Gardner says in the debate that he not only supported personhood, he also collected petition signatures at his church to put the issue on the ballot.

Voters in 2008 and 2010 defeated nearly identical personhood measures.

“The voters of Colorado have spoken on this issue,” Gardner said Friday. “To me, that’s the end of it.”

Another measure is on this year’s ballot. Amendment 67 asks: “Shall there be an amendment to the Colorado constitution protecting pregnant women and unborn children by defining ‘person’ and ‘child’ in the Colorado criminal code and the Colorado wrongful death act to include unborn human beings?”

Gardner said he stepped forward because Udall and his allies have spent the last three weeks “distorting my record.” Among the “lies,” he said: claiming that he opposes abortion even in cases of rape or incest.

“Mark Udall wants to run a social issues campaign. He definitely wants to run as the social issues candidate,” Gardner said.

“Quite frankly, I’m running a campaign on the economy and jobs and economic opportunities for the American people.”

Lynn Bartels: 303-954-5327, lbartels@denverpost.com or twitter.com/lynn_bartels

Amendment 62

Congressional candidate Cory Gardner, a Yuma Republican, said in 2010 he supported a “personhood” ballot measure and helped to collect signatures to put it on the ballot.

What it did: Sought constitutional rights for individuals “at the beginning of biological development.”

Opponents said: It would not only end abortion but also lead to a prohibition of emergency contraception in rape cases and limit treatment for miscarriages, tubal pregnancies and infertility.

Personhood supporters: Claimed opponents were exaggerating and distorting the effect the amendment, and the publicity about it had helped save lives.

Outcome: Lost by a 3-to-1 margin, the same as vote in 2008 on a nearly identical measure.