Attorneys suing the state over its recent ban on religious exemptions to vaccines for children attending school in New York wrote in a new court filing that they plan to seek documents and testimony they predict will show an animus toward religious groups from state lawmakers.

One of those attorneys said Thursday that, if allowed, they would use discovery to pursue communications about the law's enactment, and possibly depositions of the various individuals involved.

It's the latest development in the lawsuit, which is still ongoing despite a decision from a state judge that denied a preliminary injunction against the law last month.

Attorneys for the state have since filed a motion to dismiss the lawsuit, arguing the statute was well within the Legislature's authority. The law was approved by lawmakers in June after a measles outbreak rocked parts of Rockland County and New York City this year.

Michael Sussman and Robert F. Kennedy Jr., who's been publicly skeptical about the safety of vaccines, are representing more than four dozen families, all of which had previously obtained religious exemptions to vaccines, in the litigation against the state.

In a new court filing this week, they asked Albany County Supreme Court Justice Denise Hartman to reject the state's motion to have the lawsuit dismissed so they can proceed with discovery, or information they intend to pursue and use at trial.

That information, they argued in the new filing, would be used to support their theory that members of the state Legislature were driven by hostility toward certain religious groups while advocating for the measure to become law.

"For obvious reasons, defendants wish to avoid discovery in this matter," Sussman wrote. "But, the [lawsuit] plausibly alleges a plethora of cognizable constitutional challenges to the repeal legislation; dismissal would be erroneous."

Sussman, who's led arguments in the case during the last two appearances in Albany, has framed the law as an unnecessary action by state officials that was fueled by an animus, or indifference, toward certain religious groups.

Those same state officials have rejected that characterization of the statute, pointing to the recent measles outbreak, which was the largest the state had seen in decades, according to health officials.

The legislation failed to pass until June, when that outbreak was dwindling, but lawmakers stressed at the time that it was also intended to prevent a similar situation in the future.

Before the law, parents could avoid having their children vaccinated, and still attend school, by obtaining a religious or medical exemption. The new law keeps the medical exemption in place.

In its motion to dismiss the lawsuit, the Attorney General's Office stressed that lawmakers approved the measure this year after they found a correlation between the religious exemption and the measles outbreak.

While religion was part of the discussion, hostility toward any particular faith group wasn't a factor for pushing the bill to become law, the state argued.

"The statute itself and the publicly available legislative history demonstrate that public health, specifically the prevention of a further spread of a highly contagious disease, motivated the Legislature to amend the statute," the state wrote.

Sussman said in his response this week that public comments from a handful of lawmakers who supported the bill showed criticism, and sometimes hostility, toward religious groups. He said that kind of rhetoric was fuel for his challenge to the law under the First Amendment.

"This is a case which raises the question of whether a state, which has long recognized a religious exemption, may reverse that in a hail of anti-religious rhetoric and escape the scope of the First Amendment's prohibition against state action premised on religious bias," he wrote.

He rejected the state's claims that the legislation was motivated solely to benefit public health, pointing to the timing of the legislation.

While the outbreak was growing at the start of the year, lawmakers failed to approve the bill until days before the legislative session ended in June. At that point, he wrote, the law wasn't necessary to benefit public health.

"Had this matter been urgent to public health in the State, it only makes sense that these state actors, who broadly pontificate about their concern for public health, would have found a day in January, February, March or April to have enacted this legislation," Sussman said.

The state's motion to dismiss strongly rejected the notion that religious animosity was a factor in the law.

"While Plaintiffs seek to rely on isolated comments by individual legislators to establish an improper motivation for the amendment, those comments, even if they evinced hostility toward religion—and they do not—cannot be imputed to the Legislature as a whole," the state wrote.

Sussman lost on a preliminary injunction motion to immediately stop the state from enforcing the law last month but has since sought to have that decision reviewed by a higher court.

The Appellate Division, Third Department rejected his request to hear an appeal on the ruling, but Sussman is now asking for it to be considered by the Court of Appeals, the state's highest court. If that doesn't work out, Sussman says he'll try to take it to the U.S. Supreme Court.

New York Attorney General Letitia James said in a statement Thursday that her office will continue to defend the law, regardless of where the litigation takes them.

"Vaccines ensure the health and safety of our children, our families, and our communities," James said. "This law will help protect New Yorkers from experiencing any additional public health crises, which is why we continue to vigorously defend it."

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