Arguably the best-known transgender person in the world, Caitlyn Jenner, is putting her celebrity behind a political action committee that will support candidates who oppose gender surgeries for minors and transgender women competing in women’s sports.

Ms. Jenner, who won a gold medal in the decathlon at the 1976 Olympics and became a household name starring in “Keeping Up with the Kardashians,” launched her political action committee, Fairness First, this week. The PAC is described on its website as “non-partisan in nature,” though Ms. Jenner is a Republican and an outspoken supporter of Donald Trump.

“Our plan is simple,” the website says. “We will protect our children by rejecting radical gender ideology in our schools and in youth sports, from the top of the ballot to the bottom.”

Ms. Jenner, who transitioned to a female from a male in 2015, says she supports equal rights for transgender persons and runs an eponymous foundation that “promotes equality and combats discrimination” against transgender persons through grants. Yet her views on trans women in women’s sports and medical transitions for minors are unorthodox — even heretical — among most transgender activists and the left.

“No radical gender ideology! No boys in girls sports! No life altering surgeries for minors! That’s what Fairness First Pac is all about,” Ms. Jenner tweeted. She also rails against what she calls “the woke plague running rampant in this nation.”

Transgender rights activists aren’t happy. One respondent tweeted plastic surgery before-and-after photos of Ms. Jenner’s daughter, Kylie Kardashian, a beauty mogul who first enhanced her looks at age 15, with the tagline, “Life altering surgeries for minors.”

A blogger and transgender activist who works for the Transgender Law Center, Serena Daniari, tweeted, “As a trans person, when you first came out, I truly felt like you were going to be an advocate for us. Instead, you have gone on to spread lies and have thrown us under the bus constantly. You waited a lifetime to become your true self, why prevent others from doing the same?”

“The Radical Rainbow Mafia is becoming more militant by the day,” Ms. Jenner tweeted back in a long exchange with Ms. Daniari. “Not all trans people march in lockstep with their views. Diversity of thought is a good thing.”

Ms. Jenner first spoke up about her opposition to transgender women competing in women’s sports after a University of Pennsylvania transgender swimmer, Lia Thomas, won a NCAA Division I women’s championship and broke records. Winning her races by body lengths and standing on the podium with shoulders wider than any competitor, Lia Thomas’s physical advantages from having gone through male puberty were hard to ignore, her critics say.  

“We must protect women’s sports. At all costs. What Lia has done, beating biological women to win a Division I national championship, is anathema to what sports represents and the spirit of competition.” Ms. Jenner wrote in an op-ed. She called Ms. Thomas “one of the worst things to happen to the trans community.”

While Ms. Jenner’s opposition to transgender women competing in women’s sports runs counter to the views of the progressive left and transgender activists, it is in line with the majority of Americans. Nearly 60 percent of Americans think transgender women should not compete in women’s college and professional sports, according to a May 2022 Washington Post-University of Maryland poll. It finds that 68 percent of Americans say transgender women would have “a competitive advantage over other girls” in youth sports.

Lia Thomas is not the only transgender woman beating her female competition. Track, wrestling, and now golf are the latest sports to contend with this issue. This week, a transgender golfer, Breanna Gill, won the Australian Women’s Classic. Ms. Gill is now reportedly facing death threats — a testament to how virulent this debate has become.

The debate about transgender medical care for minors is even more heated, because the risks of getting it wrong are dire. The number of young people identifying as transgender has skyrocketed in recent years, leading to serious questions about how much psychological assessment and time is needed before prescribing puberty blockers, cross-sex hormones, or surgeries. Several European countries have hit pause or are rehauling their procedures for medical transitions for minors. 

Thirty states have passed or are considering legislation to restrict or ban gender-affirming care for minors, according to the Williams Institute. The issue is becoming a litmus test for politicians on both sides of the aisle.

Florida’s Board of Medicine and Board of Osteopathic Medicine, with Governor DeSantis’s blessing, both passed rules banning the use of puberty blockers, cross-sex hormones, and gender surgeries for minors. President Trump released a video on his Truth Social platform in January vowing, if elected, to punish doctors who provide medical transitions to children. “Under my leadership, this madness will end,” Mr. Trump said.

Ms. Jenner isn’t the first celebrity to face backlash for coming out against the traditional leftist orthodoxy on transgender rights, but she is one of the most high-profile. The author of the “Harry Potter” books, J.K. Rowling, is often called a “TERF” — a trans exclusionary radical feminist — for her views on transgender issues.