The 27-page complaint, filed with the the U.S. District Court in Nebraska, contends that the contraceptives mandate impedes religious liberty. “The regulation is an unprecedented invasion of the Plaintiffs’ First Amendment rights to free speech, free exercise of religion, and free association,” the states argue. They also contend that this part of the health reform law violates the Religious Freedom Restoration Act (RFRA), a 1993 law that President Clinton signed to give religious institutions greater protections.

Under RFRA, religious institutions can challenge federal laws that put a “substantial burden” on their ability to exercise a sincere religious belief. And if they can prove a substantial burden, then it’s up to the government to show two things: That the law achieves a compelling government interest and cannot be achieved in any other way that would be less restrictive on religion.

Right now, however, the biggest challenge has little to do with RFRA, and more to do with timing. It’s unclear whether the plaintiffs have actually been harmed by the policy, which is necessary to pursue legal action — or, in legalese, it’s unclear whether the case is “ripe.” While the contraceptives mandate comes online in August 2012, religiously affiliated institutions get a one-year reprieve, until August 2013. Until the provision is implemented, it may be difficult for the states to argue their First Amendment rights have actually been violated. There’s also a question as to whether states can bring this challenge on behalf of religious employers.

“I could very well see a court saying that the executive branch is trying to work on this and it may resolve some or all of these issues,” says Melissa Rogers, a senior fellow at the Brookings Institution who previously chaired President Obama’s Advisory Council on Faith-Based and Neighborhood Partnerships. “These employers are not subject to a mandate right now, so a court could decide to wait. I think that’s a big issue now.”

The Obama administration, for its part, pursued this argument in legal documents last week that responded to a challenge brought by Catholic colleges on the issue. The Department of Justice says that case should be dismissed “for lack of jurisdiction because plaintiff has not alleged any imminent injury from the operation of the regulations.”

Rogers, however, also said that if a case gets brought in late 2013, after the regulation comes into effect, it could be a different story. Then, the case will hinge on the courts’ interpretation of the substance of the case and how it relates to RFRA. They would have to answer questions like: Does requiring insurers to cover contraceptives at religiously affiliated institutions constitute a “significant burden”? Is providing birth control a compelling government interest and, if it is, can it be accomplished in a way that’s less restrictive to religion? Courts haven’t taken up these issues in previous case law, as they relate to this particular issue of providing contraceptives. That makes it difficult to predict where exactly they would land — and whether these lawsuits could ultimately take down this part of the health reform law.