SACRAMENTO — California is opening up its high school track-and-field championships in Clovis on Friday and Saturday to more girls after a transgender athlete drew controversy for qualifying for the meet.

The California Interscholastic Federation says it will allow one extra competitor in three events featuring high school junior AB Hernandez, who is trans. The group announced the temporary rule change Tuesday after President Donald Trump criticized her participation in a social media post, though the group said it decided on the rule change before that.

Here’s what to know:

State Law Lets Trans Athletes Compete

Former California Gov. Jerry Brown signed a law in 2013 allowing students to participate in sex-segregated school programs, including on sports teams, and use bathrooms and other facilities that align with their gender identity.

A Republican-led effort to block that law failed recently in the Democratic-dominated Legislature. Another proposal that also failed would have required the federation to ban students whose sex was assigned male at birth from participating on a girls school sports team.

Bill Essayli, a Trump-appointed federal prosecutor for the Central District of California, announced an investigation Wednesday into the federation and the Jurupa Unified School District, which includes Hernandez’s high school, to determine whether federal sex discrimination law was violated by allowing trans girls to compete in girls’ sports.

Federation Announces Rule Change

The federation said it was launching a “pilot entry process” to allow more girls to participate in the championship track-and-field meet. It only applies to the three events in which Hernandez is competing: triple jump, long jump and high jump.

The group says “biological female student-athletes who would have earned the next qualifying mark” at the recent qualifying event have been invited to participate in the championships. The rule change may be the first attempt nationally by a high school sports governing body to expand competition when trans athletes are participating.

If a transgender athlete medals, their ranking would not displace a “biological female” student from medaling, the federation confirmed. In high jump, triple jump and long jump, a “biological female” who would have earned podium placement will get the medal for that place and will be reflected in the records, the federation said.

The federation did not specify how they define “biological female” or how they would verify whether a competitor meets that definition.

Experts from the American Medical Association, American Psychiatric Association and American Psychological Association say gender is a spectrum, not a binary structure consisting of only males and females.

Backlash Centers on One Student

Hernandez won the long jump and triple jump during qualifying events and is expected to perform well this weekend. She also set a triple jump meet record at the Ontario Relays earlier this year.

Critics have accused her of having an unfair advantage over other athletes.

Hernandez told the publication Capital & Main earlier this month that she couldn’t worry about the critics who have called out her participation and heckled her at postseason meets.

“I’m still a child, you’re an adult, and for you to act like a child shows how you are as a person,” she said.

She noted that she has lost some of her events, saying that disproved arguments that she can’t be beat.

Rule Change Prompts Criticism

The rule change may discriminate against transgender athletes, said Elana Redfield, a policy director at the UCLA School of Law Williams Institute, which researches sexual orientation and gender identity policies.

“The CIF policy creates two sets of rules — one for transgender girls, who must earn a place through traditional measures of competition, and another for ‘biological females,’ some of whom are allowed an extra chance to earn a spot,” Redfield said in an email.

The change seems to “thread a fine needle” by trying to ensure cisgender girls aren’t denied a competition slot while still allowing trans athletes to participate, Redfield said.

Doriane Lambelet Coleman, a professor at Duke Law School, said the change would help ensure that “no female athlete loses a place on a team or in a competition when a trans girl is included.”

“Unlike inclusion policies that ignore sex differences, doing it this way doesn’t gaslight the other girls about their biology,” said Coleman, who has researches subjects including children, sports and law and wrote recently on the evolving definition of sex.

Izzy Gardon, a spokesperson for California Gov. Gavin Newsom, called the rule change “a reasonable, respectful way to navigate a complex issue without compromising competitive fairness” and said the governor thought it was a thoughtful approach. Newsom angered some liberal allies earlier this year when he questioned the fairness of transgender girls participating in girls’ sports.