AP In this photo made Monday, July 9, 2012 in St. Paul, Minn., Frank Schubert, who was a well-paid consultant, prays his daily rosary before Mass at the St. Paul Cathedral.

The latest battle in California is over 37 words. They are the final clause in a law that Gov. Jerry Brown signed this summer affirming the rights of transgender students to use facilities and play on sports teams that align with their gender identity. On Friday, groups led by the same strategist who masterminded the successful drive to ban gay marriage in California will submit a petition to the state that could lead to the landmark measure being overturned.

Opponents of the statute, the first of its kind in the United States, say the language is too broad and that it neglects the privacy rights of most students for the benefit of a few. Supporters say the measure helps foster acceptance for transgender students, who can feel alienated by the rigid gender distinctions of his-or-her bathrooms and school sports teams.

The law’s challengers need to submit 505,000 valid signatures from California residents, roughly 5% of voters who cast ballots in the most recent governor’s race, to get a referendum to overturn it on the ballot in November. Frank Schubert, the consultant who spearheaded the Proposition 8 effort to ban gay marriage that was overturned by the Supreme Court this summer, has rallied social conservatives. He says by Monday they hope to turn in more than 700,000 signatures, amassed over three months by volunteers, paid workers, direct mail and more than 750 churches.

Here is the passage at the heart of the matter:

A pupil shall be permitted to participate in sex-segregated school programs and activities, including athletic teams and competitions, and use facilities consistent with his or her gender identity, irrespective of the gender listed on the pupil’s records.

Schubert says there would not be a push for a referendum if the language had included more caveats, like requiring that transgender students had an established history of presenting themselves as male or female. As it’s worded, he believes that non-transgender teenagers will abuse the law, though he concedes there are no documented cases to back up those fears. “Somebody claiming to be a girl can go into the girls’ showers and bathroom and the locker room and can play on the girls sports team,” he says. “There are no procedures to balance the interest of all students.”

Some of the law’s supporters, like Geoff Kors, paint organizations pushing the referendum as “LGBT hate groups.” Kors, a policy strategist for the National Center for Lesbian Rights, says that fighting against the law only hurts the population at the center of the debate. “Just their doing that is harmful to transgender students who are trying to go to school and fit in with their classmates,” he says. “They’re hearing these horrific messages about who they are.”

California already had numerous anti-discrimination laws on the books. Schubert sees the existing measures as evidence that this one is unnecessary, as well as “offensive” in its unqualified terms. Kors acknowledges that other legal precedents, like a case settled by the Department of Justice this summer, can be used to require similar access to facilities and programs. But this measure, he says, is useful in providing such “unambiguous language that we wouldn’t have to continue to bring lawsuits against schools to get them to enforce the law.”

A more fundamental point of contention is whether gender is a flexible social construct or a fixed fact. “We introduce this concept called gender identity and I don’t have any idea what that is,” Schubert says. “You can change your appearance, you can change your presentation. You cannot change your gender.” Ashton Lee, a transgender student in California who has become an outspoken advocate for the law, describes being transgender as trying to match his body to what he feels in his heart and mind. “There are some people who are confused by the idea,” he says, “and there are some people who are unwilling to accept the idea.”

The high school junior recently filed a legal complaint with his mother against one of the groups pushing the referendum. Lee says that though the law doesn’t go into effect until Jan. 1, the awareness it created has already helped inspire changes at his school—including his use of the boys’ bathroom. “It just feels better than having to be the kid that uses the staff bathroom or being the boy in the girls bathroom or not being about to use it at all,” he says. “It’s just helps get me to being normal at my school.”

The fight in California comes as Washington remains deeply divided over matters of gay rights. On Nov. 7, the U.S. Senate passed legislation extending workplace protections to the LGBT community. Like Schubert, House Republicans who oppose the measure argue that necessary anti-discrimination measures are already in place. Obama has urged the House to pass the bill.

It will be weeks, at the earliest, before California officials count and validate the signatures submitted this weekend. If the threshold is passed, the law will be suspended until the vote next November. And the campaigning, on both sides, will begin.