A number of lawsuits are now underway in North Carolina over its enforcement of HB2, the controversial law that, among other provisions, bars transgender students from using restrooms that align with their gender identity.

The main two are the federal government's action against North Carolina and the state's own pushback against the Justice Department for "overreach" -- each raising differing interpretations of whether federal civil rights law should be read to protect trans students.

But a third legal challenge, filed by North Carolinians for Privacy, a group of students and parents who support the law, has flown under the radar -- perhaps because the parties involved aren't nearly as prominent as Attorney General Loretta Lynch or North Carolina Gov. Pat McCrory (R).

Their stake in the controversy shouldn't be ignored, if only because they invoke the constitutional right to privacy -- a fundamental right that for more than half a century has been widely recognized as a liberal landmark. Except this coalition of students and parents isn't exactly liberal.

The group's 50-page complaint more or less asks a federal court to declare that the Obama administration overstepped its administrative and enforcement authority under existing law, and that federal officials shouldn't take action against North Carolina because that would harm the students and the parents who benefit from the funding their schools receive from the government.

Whether these claims have merit will be decided by the courts in due time. Until then, a curious legal argument will take center stage in the litigation: that the federal government's opposition to North Carolina's law somehow invades students' "constitutionally guaranteed right to bodily privacy."

Those words or similar language are found throughout the lawsuit, which more than once presses the notion that the federal government's actions in favor of trans students violate the Constitution.

As a result of the government's overreach, students "will suffer the loss of their constitutional right to privacy, because they will be compelled by the government to use restrooms and locker rooms with members of the opposite sex," wrote lawyers for the faith-based Alliance Defending Freedom, a legal advocacy group representing the plaintiffs.

The "right to privacy" is a peculiar claim for Alliance Defending Freedom, which over the years has supported "religious freedom" litigation before the Supreme Court and lower courts in a number of high-profile disputes. A recent Mother Jones report suggested the group may have played a role in the wave of similar bathroom bills appearing in a number of states.

The reason ADF's appeal to "bodily privacy rights" or the "fundamental right to privacy" may seem out of place -- especially in light of recent constitutional history -- is the lack of an explanation for where the right comes from. The lawyers provide no legal citations or support for its source.

Matt Sharp, one of the ADF lawyers representing the students, tried to make a layman's case for privacy and his clients in an online op-ed in The Daily Signal, but he sidestepped explaining the constitutional source for his position.

"Why does privacy even matter? Sure, our courts have recognized that it’s a constitutionally protected right. And our society has long structured itself around the need to allow privacy for the sexes in intimate settings," Sharp wrote, but stopped short of delving much deeper.

A possible explanation for the omission is that the right to privacy is not explicit in the Constitution. Instead, the Supreme Court has recognized it for the past 50 years in a line of cases that are traditionally regarded as liberal -- such as the landmark Roe v. Wade, which legalized abortion, and Lawrence v. Texas, which struck down bans on consensual sex between gay adults across the nation.

Griswold v. Connecticut, the leading 1965 precedent recognizing the right to privacy, featured prominently in these and other decisions expanding on why privacy matters so much for a person's dignity and intimacy -- including last summer's Obergefell v. Hodges, which declared that gay couples have a constitutional right to marry.

There is no right to privacy. Justice Antonin Scalia

The late Justice Antonin Scalia, who roundly rejected atextual readings of the Constitution, dissented in these cases time and again, and in 2013 went as far as to state that "there is no right to privacy" and that the Supreme Court was wrong to ever say that there was. Legal minds on the right generally hold to that view.

Does this mean religious conservatives are embracing the right to privacy anew, or is it simply litigation strategy in the wake of their support of North Carolina's bathroom bill?

Sharp, the ADF lawyer, explained in an interview that the specific goal of the North Carolina litigation isn't to build on these historic precedents, which his organization continues to oppose.

"Those cases have taken" the right to privacy "and twisted it to justify taking human life," he told The Huffington Post, in a reference to the Roe decision.

Instead, he said, the fundamental right his organization is advocating for is rooted in the part of the Constitution that protects citizens against unreasonable searches and seizures.

Bloomberg via Getty Images Alliance Defending Freedom has taken a lead role in several path-marking Supreme Court cases dealing with religious freedom, including Burwell v. Hobby Lobby in 2014.

"The right we refer to is one that dates back to the founding," he said. "It's rooted in the Fourth Amendment, saying that the government can't come in and search your person or your property without having a compelling reason or a warrant for doing so."

The Supreme Court and lower courts typically examines Fourth Amendment cases in the context of criminal prosecutions and investigations. But Sharp said that if one goes farther back in history, there is legal support for a kind of personal privacy that transcends the kind the high court advanced in the 1960s and onward.

"There are court cases from the 1850s that talk about the right to privacy — that the government can't come in and basically force you to expose yourself," he said, adding: "That's the original understanding of the right to privacy, not how it's more recently been interpreted by the court to something far beyond our founders ever envisioned."

Though the students' case against the federal government is still at a very early stage, Sharp said he and his team hope to explore this more "traditional understanding" of the right to privacy as the case moves forward.

"That's what we're harkening back to," he said. "We're not disputing what the court has done in Griswold and some of those other cases. We obviously still disagree with those. We're harkening back to something more traditional -- more foundational in our nation's history."

Asked if his organization would like to do away with the more modern reading of privacy in the coming litigation, Sharp demurred.

"Not directly in these cases," he said. "In other ones? Yeah, especially obviously in the abortion context. We disagree with those. This is sort of a different battle."