Kansas Senator Roger Marshall on Wednesday introduced a bill taking aim at the core tenants of transgender ideology by defining “male” and “female” in terms of “biological truth.”

The “Defining Male and Female Act of 2024” would enshrine in law the biological differences between men and women. The proposed legislation, which is backed by a handful of conservative organizations, says the definition is required to combat “increasing confusion about the definition of sex as a biological truth.”

Marshall reiterated that goal to The Daily Wire.

“As a physician who has delivered over 5,000 babies, I can confidently say that politicizing children’s gender to use them as pawns in their radical woke agenda is not only wrong, it is extremely dangerous. I didn’t think we would need legislation to tell us that there are only two sexes: male and female, but here we are,” Marshall said.

Marshall is the latest House Republican to introduce legislation on this issue. Rep. Nancy Mace (R-SC) this month introduced a measure to keep men out of the women’s bathrooms in the U.S. Capitol. That bill would ensure that incoming Democrat Rep. Sarah McBride (DE), a man who identifies as a woman, could not use the same bathrooms as his female colleagues.

Marshall’s bill notes that “every individual is either male or female” and that “in no case is an individual’s sex determined by stipulation or self-identification.” It defines a female as “an individual who naturally has, had, will have, or would have, but for a congenital anomaly or intentional or unintentional disruption, the reproductive system that at some point produces, transports, and utilizes eggs for fertilization.”

It defines a male as: “an individual who naturally has, had, will have, or would have, but for a congenital anomaly or intentional or unintentional disruption, the reproductive system that at some point produces, transports, and utilizes sperm for fertilization.”

This makes a “man” an “adult human male” and a “woman” an “adult human female.” 

Marshall’s legislation is backed by Idaho Republican Sens. James Risch and Mike Crapo and Sen. Cindy Hyde-Smith (R-MS). Rep. Mary Miller (R-IL) is set to introduce a companion bill in the House. Conservative groups including Heritage Action, Family Research Council, Concerned Women of America, and Alliance Defending Freedom also support the proposal. 

“We must codify the legal definition of sex to be based on science rather than feelings,” Marshall told The Daily Wire. “With our legislation, we can fight back against the Biden-Harris Administration’s assault on our children.”