Illinois’ new Citizen Participation Act — a little extra legal muscle behind the First Amendment — just got its first courtroom workout in “the case of the confiscated mezuzah,” which you can read about here. And there’s more on the act  here. Now it’s making an appearance in a dispute with a much higher profile — the one between Planned Parenthood and opponents of the clinic it’s now operating in Aurora.

Planned Parenthood is being sued for defamation by 17 people who say they’re members of the ad hoc Fox Valley Families Against Planned Parenthood, and by the Chicago-based Pro-Life Action League, founded by Joseph Scheidler in 1980. Scheidler’s son Eric, who lives in Aurora and spearheaded Fox Valley Families, is one of the 17 plaintiffs.

The plaintiffs claim that Planned Parenthood defamed them last September in a letter from its Chicago-area president, Steven Trombley, that advised Aurora’s mayor and aldermen that Pro-Life Action League “activists . . . have a well-documented history of violence against both persons and property as well as other related criminal activity,” and in an ad published in the Aurora Beacon News. The ad was headlined “Don’t Let the Extremists Deny Vital Health Care to the People of Peoria” and it warned, “Joe Scheidler and his Pro-Life Action League have a well-documented history of advocating violence against both persons and property, as well as other related criminal activity.” (Among other things, the suit says Joe Scheidler played no role in the Aurora protest.)

This past Wednesday, Planned Parenthood filed a motion asking the Kane County circuit court to dismiss the lawsuit. The brief arguing this motion makes interesting reading. Patrick Donnelly, a Chicago attorney who recently found himself looking down the business end of the Citizen Participation Act told me, “Not to sound like a gun nut, but there are enough laws [already] on the books that if someone sues someone improvidentially, someone can take a whack back at them.” He might point to the Planned Parenthood brief for support. It argues for dismissal on a variety of familiar grounds: because the allegedly defamatory statements were true, because they can be given an innocent construction, because they didn’t even refer to the individual plaintiffs.

But leading the list is the assertion that the Citizen Participation Act gives Planned Parenthood “absolute immunity against plaintiffs’ claims.” That’s because the organization was campaigning for local political support, and the CAP — to quote it — provides that “acts in furtherance of the constitutional rights to petition, speech, association, and participation in government . . . are immune from liability, regardless of intent or purpose” (emphasis from Planned Parenthood’s attorney, Alan Gilbert of Sonnenschein Nath & Rosenthal).

In time, a series of judicial rulings will establish just how much sway the CAP enjoys in Illinois courts. Now, when it’s brand new, briefs don’t just cite the act, they try to sell its splendors to judges who have never met it before. “By creating this broad scope of protection for any speech aimed at procuring favorable government action,” the Planned Parenthood brief informs circuit judge Judith Brawka, “Illinois’ General Assembly was even more expansive in its language” than other states had been. (The brief cites the ruling in the mezuzah case, the one and only interpretation of the CAP by an Illinois court so far.)

Attorney Alan Gilbert tells me that Judge Brawka seems well aware of her opportunity to put her stamp on the law. “I can tell she’s very intrigued by its newness,” he says. “It’s something out of the realm of garden variety foreclosure actions” — more typical fare in the courtrooms of Kane County.