Is the conservative consensus crumbling over gay marriage?

This week, newly-unearthed internal memos revealed that a leading group fighting gay marriage, the National Organization for Marriage, sought to drive "a wedge between gays and blacks," among other divide-and-conquer tactics, to stop same-sex unions.

But opponents of gay marriage are facing a rift of their own: The defection of libertarian conservatives from the cause.

In North Carolina, two leading conservatives in the state made public statements this week opposing Amendment One, the far-reaching ballot measure that will be voted on May 8, and another GOP leader admitted the law will likely be overturned within 20 years.

The cracks in the conservative coalition first emerged on March 26, when John Hood, president of the John Locke Foundation -- a think tank largely funded by Republican donor Art Pope -- described the amendment as "unwise and unfair."

Responding to the controversy over the Locke Foundation's publishing of an offensive photo by Locke blogger Tara Servatius, which showed President Obama in apparently gay drag gear next to a bucket of Kentucky Fried Chicken (Servatius later resigned, although she maintained she did nothing wrong), Hood wrote this:

I think amending North Carolina’s constitution to forbid gay and lesbian couples from receiving any future legal recognition, including civil unions, is unwise and unfair. In my opinion the real threat to marriage is not the prospect of gay people getting hitched. It is the reality of straight people too quickly resorting to divorce, or never getting hitched in the first place.

In covering Hood's statement, reporters turned to another prominent libertarian-leaning conservative, Bob Orr, a former state Supreme Court Justice who used to lead another Pope-backed project, the N.C. Institute for Constitutional Law.

Orr predicts the amendment won't endure legal scrutiny; as he told reporters:

Any provision that has to be put into the ‘miscellaneous’ section of the constitution immediately raises questions about whether it should be in the state constitution. It’s probably not a provision that ought to be in.

Oddly enough, that sentiment was echoed by none other than N.C. Republican House Speaker Thom Tillis, who in 2011 led the effort to bring the Amendment One ballot measure to the house floor and voted in favor of it.

Speaking to a group of students this week, Rep. Tillis predicted Amendment One would pass in May but repealed in 20 years because of changing views about gay marriage, saying:

It's a generational issue. If it passes, I think it will be repealed within 20 years.

It wasn't a one-time misstatement: Tillis' spokesman later confirmed it accurately reflected the lawmaker's views.

But supporters of the amendment still have some advantages. Polls still show a majority of N.C. voters support the amendment -- although that appears to be diminishing, especially among independents, who may or may not be motivated to vote in the May primaries.

And despite the statements of opposition from John Hood and Bob Orr, the groups pushing the amendment also still have the financial backing of millionaire retail magnate Art Pope.

Art Pope's family foundation has given nearly $1 million to the group leading the push for the amendment in North Carolina, the N.C. Family Policy Council. The group has spearheaded the drive for an anti-gay marriage amendment in NC since 2004, and Pope's funding has grown in lockstep with the Council's involvement with the gay marriage debate.

More recently, a conference held by the Civitas Institute -- which receives most of its money from Pope's foundation -- was the launching ground for a "Values Bus" tour aiming to rally amendment supporters across the state.

The "Values Bus" tour was organized by the national Family Research Council, which has been designated as a hate group by the Southern Poverty Law Center, and the lobbying arm of the Heritage Foundation -- both of which receive support from Pope's foundation.

Art Pope has yet to personally weigh in on the amendment, but his money is doing the talking.