Charlie Baker continues to be on the hot seat as Republican senators and women’s advocacy organizations push the former Massachusetts governor to allow only “biological females” to compete in NCAA women’s sports.

Baker, who became NCAA president after leaving Beacon Hill last year, received a letter from 23 Republican senators on Tuesday, urging him to update the NCAA’s student-athlete participation policies as the Biden-Harris administration implements its Title IX rewrite.

“The science is clear,” states the letter led by U.S. Sen. Marsha Blackburn, R-Tennessee, and signed by 22 Republican colleagues. “Males have inherent athletic advantages over females due to their anatomy and biology.”

New Title IX regulations went into place at the beginning of the month after the Biden-Harris administration, in the spring, rewrote the landmark 1972 law that prohibits sex-based discrimination in institutions that receive federal funding.

The updated regulations include protections for LGBTQ+ students, an expanded definition of sexual harassment at schools and colleges, and safeguards for victims.

In their letter, the Republican senators highlighted how they believe the NCAA has “still taken no steps to protect” female student-athletes. The Title IX rewrite has gone through in just 24 states, with Republican attorneys general fighting the regulations in 10 lawsuits to block them in the 26 other states.

“Consistently, when adult males’ athletic performance is contrasted with adult females’ athletic performance in sports relying on endurance, muscle strength, speed, and power, males dominate, outperforming females by 10 to 30%,” the letter states.

Education Secretary Miguel Cardona emphasized on Aug. 1 how the regulations “clarify that Title IX’s prohibition of sex discrimination includes all forms of sex discrimination.”

“It’s unacceptable that any student has to give up on their dreams of a college degree because they’re pregnant,” he said, “and it’s unacceptable that any student face discrimination or bullying simply because of who they are.”

Republican senators also in their letter stressed how the National Association of Intercollegiate Athletics Council of Presidents approved a policy in April that prohibits the participation of males in women’s sports.

That came before the Court of Arbitration for Sport ruled Lia Thomas, a swimmer who became the first openly transgender athlete to win a Division I national championship, lacked standing to challenge a World Aquatic policy, preventing Thomas from the Olympics.

“While men may have inherent athletic advantages, they have no advantage over women in their level of passion, drive, or desire to compete,” the Republican senators state.