The Main Witness Against Gay Marriage and Pro- Prop 8 Comes Out Against

 - The chief witness who testified in favor of California's gay marriage ban during a landmark trial on the measure's constitutionality reluctantly came out in favor of gay and lesbian unions on Friday, saying he now thinks "that the time for denigrating or stigmatizing same-sex relationships is over."

In an opinion piece published in The New York Times (http://nyti.ms/Lo6a6V ), Institute for American Values president David Blankenhorn partly attributed his change of heart to a recognition that years of opposing same-sex unions had done nothing to strengthen the institution of marriage among heterosexuals.

"I had also hoped that debating gay marriage might help to lead heterosexual America to a broader and more positive recommitment to marriage as an institution. But it hasn't happened," Blankenhorn wrote. "If fighting gay marriage was going to help marriage over all, I think we'd have seen some signs of it by now."

Human Rights Campaign President Chad Griffin, who spearheaded the lawsuit challenging the voter-approved ban on behalf of two same-sex couples that led to Blankenhorn's testimony, applauded his former adversary's conversion on the issue.

"While it can be difficult as a public figure to change course, I applaud him for taking a courageous and principled stand. His experience wrestling with the issue of marriage equality and coming out on the right side of history will be an inspiration to millions of fair-minded Americans who are in the same place," Griffin said.

The lead defense attorney for the ban, known as Proposition 8, issued a statement minimizing the impact of his former witness' words.

"While we strongly disagree with the position Mr. Blankenhorn has now taken, his change of view, much like President Obama's evolution, brings into sharp focus that people of goodwill, with malice toward none, can disagree in good faith and that the courts should not foreclose the continuing debate currently taking place across the country on this vitally important issue," Charles Cooper, who represents Proposition 8's sponsors, said.

Blankenhorn's reversal is likely to have more of a public relations effect than a legal one in the gay marriage debate. The federal judge who presided over the 2010 trial disqualified Blankenhorn as an expert witness, saying he was more of a commentator than a researcher and that his testimony had not been cogent.

An appeals court affirmed the trial judge's conclusion that the ban was unconstitutional. Proposition 8's sponsors said this month that they plan to appeal to the U.S. Supreme Court.

Blankenhorn, an author whose New York-based think tank has been one of the traditional marriage movement's most consistent, if moderate voices, was one of two witnesses that lawyers for the sponsors of California's same-sex marriage ban called to the stand in January 2010. With that proceeding, the voter-approved measure became the subject of the first federal trial to examine if laws limiting marriage to a man and a woman violate the civil rights of gays and lesbians.

During two days of testimony, he repeatedly stated that the rights of same-sex couples should come second to preserving the cherished, social institution of marriage based on the moral imperative of maximizing opportunities for allowing children to know both their biological parents.

But he became combative and jumbled during an exhaustive cross-examination, eventually allowing that permitting gay couples to wed was consistent with the American values of equality and fairness.

In his New York Times commentary, Blankenhorn wrote that while he still thinks children benefit from knowing both their biological parents, he has concluded that it is just as important for same-sex couples to be treated equally under the law.

"I don't believe that opposite-sex and same-sex relationships are the same, but I do believe, with growing numbers of Americans, that the time for denigrating or stigmatizing same-sex relationships is over," he said.

Another factor in his endorsement of same-sex marriage, Blankenhorn said, was what he termed "an underlying anti-gay animus" among "much of the opposition to gay marriage."

"As I look at what our society needs most today, I have no stomach for what we often too glibly call 'culture wars.' Especially on this issue, I'm more interested in conciliation than in further fighting," he said.

By LISA LEFF