Who’s angrier about this? Traditional marriage activists, or gay rights activists who don’t want to see the debate about same-sex marriage dragged down the slippery slope when they’re trying to build on momentum from New York?

Nationally-known constitutional law professor Jonathan Turley said the lawsuit to be filed in U.S. District Court in Salt Lake City will not call for plural marriages to be recognized by the state. Instead, it asks for polygamy between consenting adults like his clients, former Utahn Kody Brown and his wives, to no longer be considered a crime.

“We are only challenging the right of the state to prosecute people for their private relations and demanding equal treatment with other citizens in living their lives according to their own beliefs,” Turley said in a press release. The Browns star in the TLC network show “Sister Wives.” There is no word yet on whether they will appear in a press conference scheduled for Wednesday…

The complaint to be filed Wednesday, Turley said, presents seven constitutional challenges to the state’s bigamy law. It is largely based on the right to privacy.

“In that sense, it is a challenge designed to benefit not just polygamists but all citizens who wish to live their lives according to their own values—even if those values run counter to those of the majority in the state,” said Turley, a member of the faculty at George Washington University.

If the distinction between decriminalization and state recognition seems confusing (which it did to me at first), it helps to know that Utah’s bigamy statute includes cohabiting with one person when you’re legally married to another. And in fact, this guy is only legally married to one woman; the other three are, er, “sister wives.” Basically, he’s arguing that he doesn’t care if the state recognizes them as legal spouses or not, just that he doesn’t want the cops to come knocking and lock him up when they find out. In that sense, his court claim mirrors the current legal regime in most states where gay marriage is banned but gay sex is constitutionally protected.

So, no lawsuit to legalize polygamous marriage — yet. But legal precedents have a funny way of building on each other:

The lawsuit is not demanding that states recognize polygamous marriage. Instead, the lawsuit builds on a 2003 United States Supreme Court decision, Lawrence v. Texas, which struck down state sodomy laws as unconstitutional intrusions on the “intimate conduct” of consenting adults. It will ask the federal courts to tell states that they cannot punish polygamists for their own “intimate conduct” so long as they are not breaking other laws, like those regarding child abuse, incest or seeking multiple marriage licenses…

The questions surrounding whether same-sex couples should be allowed to marry are significantly different from those involved in criminal prosecution of multiple marriages, Ms. Pizer noted. Same-sex couples are seeking merely to participate in the existing system of family law for married couples, she said, while “you’d have to restructure the family law system in a pretty fundamental way” to recognize polygamy.

Professor Turley called the one-thing-leads-to-another arguments “a bit of a constitutional canard,” and argued that removing criminal penalties for polygamy “will take society nowhere in particular.”

Ah, but they’re not asking to change family law, just to take polygamy out of the penal code. The family law case will be the next lawsuit. FYI, the Supreme Court already upheld laws against polygamy — 130 years ago, rejecting a Mormon challenge based on the Free Exercise Clause. So there’s precedent here if SCOTUS wants it when it eventually hears a case along these lines. Two important footnotes, though. One: The Court’s language in Lawrence v. Texas, a decision authored by Anthony Kennedy, was famously broad in its implications (a point noted by Scalia in dissent at the time), so there’s no telling whether that earlier precedent is still good law. And second, Lawrence itself overruled a much more recent precedent in Bowers v. Hardwick to arrive at its holding. So yeah, there’s quite a fair chance that the Brown clan might pull this off.

Exit question: Speaking of people who aren’t eager to watch this court/media battle play out, how excited do you think Mitt Romney and Jon Huntsman are right now?