I’m tempted to call this a clever Cheney family ploy to burnish Liz’s conservative credentials ahead of her primary against Mike Enzi, except … Enzi’s opposed to gay marriage too. It may help her pass a tea-party litmus test but it doesn’t actually gain her anything against the incumbent. On the contrary, all the attention to this subject is likely to remind Wyoming conservatives not only that the Cheney family is notably pro-gay among Republican royalty — Dick Cheney’s other daughter is herself married to a woman — but that Liz herself was widely assumed to be pro-SSM based on things she’s said in the past. Either (a) everyone misunderstood her position before, (b) she’s an exceedingly rare example of someone who used to support gay marriage but has since “evolved” in the other direction, or (c) her endorsement of traditional marriage on “Fox News Sunday” is just an empty pander to tea partiers.

Here’s Heather Poe, who’s married to Liz’s sister Mary, responding to her opposition of SSM yesterday on Facebook. I wonder which of the three explanations above she favors.

I was watching my sister-in-law on Fox News Sunday (yes Liz, in fifteen states and the District of Columbia you are my sister-in-law) and was very disappointed to hear her say “I do believe in the traditional definition of marriage.”

Liz has been a guest in our home, has spent time and shared holidays with our children, and when Mary and I got married in 2012 – she didn’t hesitate to tell us how happy she was for us.

To have her now say she doesn’t support our right to marry is offensive to say the least

I can’t help but wonder how Liz would feel if as she moved from state to state, she discovered that her family was protected in one but not the other.

I always thought freedom meant freedom for EVERYONE.

Mary Cheney, Liz’s sister and Poe’s spouse, replied, “Couldn’t have said it better myself.” Legit sibling feud or campaign charade aimed at highlighting Liz’s ostensible social conservatism? The NYT thinks it’s the former:

The situation has deteriorated so much that the two sisters have not spoken since the summer, and the quarrel threatens to get in the way of something former Vice President Dick Cheney desperately wants — a United States Senate seat for Liz…

People who have spoken to Liz Cheney say she is irritated that her sister is making their dispute public and believes it is hypocritical for Mary Cheney to take such a hard line now, given that she worked for the re-election of President Bush, an opponent of same-sex marriage…

Mary Cheney, 44, said in a phone interview Sunday that she presumed her sister shared her father’s views on marriage, and that view was reinforced because Liz Cheney “was always very supportive” of her relationship with Ms. Poe and the couple’s two children. She learned otherwise in August when Liz Cheney declared, shortly after announcing her Senate candidacy, that she was opposed to same-sex marriage rights. Mary Cheney said it is now “impossible” for the sisters to reconcile as long as Liz Cheney maintains that position.

“What amazes me is that she says she’s running to be a new generation of leader,” Mary Cheney said, citing her 47-year-old sister’s slogan in her campaign against Mr. Enzi, 69. “I’m not sure how sticking to the positions of the last 20 or 30 years is the best way to do that.”

That last paragraph is the killer, since one of Liz’s big headaches in the primary is reassuring primary voters that she’s a bona fide conservative and a bona fide Wyomingite. Enzi and his surrogates, like Rand Paul, have needled her about her east-coast pedigree, knowing that calling her authenticity into question on one point may lead voters to question it on the other. Liz’s counter to all that is that the Senate needs new blood; now here comes Mary Cheney to question whether Liz’s supposed advantage over Enzi — youth and fresh thinking — is much of an advantage after all. Result: Some social-con voters may doubt whether Liz is really as much a supporter of traditional marriage as she says and others may doubt whether she’s really that much different from Enzi. Not a good place to be — especially with Enzi getting good press lately for his early skepticism of ObamaCare and reaching out to tea partiers by publishing op-eds at sites widely read by grassroots conservatives.

Here’s what she said yesterday, and beneath it is what she said in 2009. She never explicitly says in the latter that she supports legalizing gay marriage, but she does say that her “family” endorses the idea that “freedom means freedom for everyone” — the very words that Poe threw back at her in yesterday’s Facebook post. Draw your own conclusions about what her position was at the time.