A bill has landed on the desk of South Dakota governor Dennis Daugaard, a Republican who has given the bill a positive nod in the past. Daugaard’s signature is the last remaining step before South Dakota could become the first state to specifically target transgender youth by passing a law that would require the gender assigned at birth to indicate which bathrooms and locker rooms a student may use.

The bill, which was introduced by Republican state Senator Fred Deutsch, passed Tuesday in the state senate in a 20-15 vote. Last month it passed in the House, 58-10.

“This is such the right thing to do to protect all of our students,” Dale Bartscher, spokesman for the conservative Christian group Family Heritage Alliance Action, said in support of the bill. “It’s a privacy bill, it’s a modesty bill, it’s sensible South Dakota common sense.”

Republican state Senator David Omdahl claims that his bill will “preserve the innocence of our young people.”

Under Deutsch’s bill, schools would need to create single-occupancy bathrooms in order to provide a “reasonable accommodation” to transgender students. If they wanted to use a different bathroom than their birth certificates would indicate, schools must approve a written request.

Opponents say the bill targets the most underrepresented and vulnerable students. The LGBT-rights group Human Rights Campaign and the The American Civil Liberties Union of South Dakota have spoken out vociferously against the bill.

“History has never looked kindly upon those who attack the basic civil rights of their fellow Americans, and history will not treat kindly those who support this discriminatory measure,” said Chad Griffin, Human Rights Campaign president.

Sarah Warbelow, the HRC legal director, urged Daugaard to meet with a few transgender kids and hear their concerns before making up his mind. Daugaard returned the comment that he did not believe he had ever met a transgender individual and likely would not before coming to a decision.

Rebecca Dodds, the mother of a transgender son who recently graduated from high school in the state’s famed Black Hills, said compelling students to use a separate facility could force them to out themselves to their peers, which could lead to harassment or violence. “For my son, I wouldn’t want him to go to school as a boy and be questioned by other students about why he can’t just go to the bathroom with the other boys,” she says. “He was afraid to tell me and I’m his mom … It’s really awful to think about your child being the one that they’d say, ‘Okay, everybody, go to the locker room—but not you.’”

Dodds told Time magazine that the law would cause social isolation if it goes into effect. She says she realized her child was getting urinary tract infections and related health problems because it was simply so uncomfortable for him to enter the girls restroom, so he stopped going to the bathroom at school.

South Dakota is one of at least five other states that are considering bills that place importance on children’s genitalia in determining their rights.