04/12/2012 03:21 pm ET Updated Feb 02, 2016

David Blankenhorn, Pro-Proposition 8 Witness, Comes Out Against North Carolina's Same-Sex Marriage Ban

The opposition to a proposed constitutional amendment in North Carolina that would ban same-sex marriage is widening.

David Blankenhorn, who testified in court in 2010 in defense of California's same-sex marriage ban, coauthored an op-ed in the Raleigh-based News & Observer on Wednesday, arguing that North Carolina's proposed ban would go "too far" because it also bans civil unions. California's law allowed for such unions.

As president of the Institute for American Values, a pro-marriage advocacy group, Blankenhorn noted in the opinion piece that North Carolina's proposal would "convince people that the real agenda of marriage advocates is not protecting marriage, but ignoring and ostracizing gay people."

Both Blankenhorn and his coauthor, North Carolinia-raised Elizabeth Marquardt, the institute's vice president, describe themselves as "native Southerners." They stated that they are against legalizing same-sex marriage. But they drew a sharp distinction between opponents of same-sex marriage and those against any legal recognition of same-sex couples.

"In the California 'Prop 8' case," the op-ed explained, Blankenhorn "felt that he could testify on behalf of traditional man-woman marriage in good conscience, in part because California some time ago passed domestic partnership legislation to extend legal recognition to same-sex couples."

The piece also said Blankenhorn "argued in favor of domestic partnerships, more commonly called civil unions, while also insisting that marriage, because of its unique role in uniting biological, social and legal parenthood –- a great gift to our children –- is its own institution, deserving of its own name, and should remain, as it has always been, the union of a man and a woman."

"There are people who oppose same-sex marriage and people who oppose homosexuals themselves," Marquardt told The Huffington Post on Wednesday. "If you want to understand why young people increasingly and dramatically support same-sex marriage, I think, it's because they see the ugliness of bigotry in this debate and are repelled."

In North Carolina, same-sex marriage is already illegal. The proposed amendment, which North Carolinians will vote on next month, would formally define marriage as being between a man and a woman in the state's constitution and preclude any future legislation to introduce domestic partner protections or other benefits for same-sex couples. It would also remove existing domestic partner benefits now available in some parts of the state.

The proposed amendment states, "Marriage between one man and one woman is the only domestic legal union that shall be valid or recognized in this state."

Proponents of the bill argue that the broad-reaching language of the bill is necessary.

"One of the things that we're trying to do -- that I think we're successful in doing -- is not just protecting the word of marriage but the institution of marriage," said state Sen. Daniel Soucek, a Republican sponsor of the bill.

Soucek disagrees that the amendment is bigoted and believes the impact of the amendment, if passed, would be minimal. "The day after this amendment is voted on, if this passes, there won't be any perceivable change in the lives of people in North Carolina," he said. "I don't see it as having a negative."

A bipartisan group of politicians, businesspeople, legal experts and citizens disagree, arguing that the amendment is unnecessary and could lead to a wide array of unintended, and harmful, consequences in the legal system.

Blanekenhorn and Marquardt, who have devoted their careers to "protecting marriage," also see harmful consequences in the language's amendment -- for opponents of same-sex marriage.

"My concern about this amendment is that it links understanding marriage as being about mothers and fathers with anti-gay bigotry very explicitly," Marquardt told The Huffington Post. "The worry that I have about same-sex marriage is not about homosexuality at all but about how redefining marriage might affect heterosexual couples. And allowing civil unions doesn't enter into that."

Opponents of North Carolina's amendment welcome Marquardt and Blanekenhorn's support. "The argument they're making is in line with the majority of North Carolinians who may not be there on the marriage issue yet but are certainly there with equal rights under the law," said Nation Hahn, digital media director for the Coalition to Protect North Carolina Families.

A recent survey by North Carolinians by Public Policy Polling showed that 51 percent of voters supported some form of legal recognition for same-sex couples, while only 45 percent completely opposed any such recognition.

Among many advocates for marriage equality, some of Blankenhorn and Marquardt's views have been highly controversial. When Blankenhorn testified in California, he argued that legalizing same-sex marriage harms heterosexual marriage and has a negative effect on children. Advocates for same-sex marriage have pointed out that he failed to produce any evidence that this has happened.

"It's an impossible assertion to prove either way," said John Culhane, a law professor at Widener Law School. "It's also not an argument that is likely to impress a court."

CORRECTION: This report has been updated to reflect that David Blankenhorn testified in defense of California's same-sex marriage ban. An earlier version had indicated that he had testified against it. Blankenhorn's organization is now properly rendered as the Institute for American Values; an earlier version referred to it as the Institute for Family Values.