He must sign it into law or veto it by March 1 — but if he does nothing, the measure will become law without his signature, making South Dakota the first state in the country to restrict bathroom and locker room use by transgender people.

by Bill Kirkos

Sioux Falls, South Dakota (CNN) - Just like any other high school senior, 18-year-old Thomas Lewis is looking forward to life after graduation.

He’s considering attending the University of Minnesota in the fall and studying linguistics, something his mother thinks might be his true calling due to his love of languages.

However, while other teens at Lincoln High School in Sioux Falls, South Dakota, might be thinking right now about prom and graduation day, Lewis has been taking time off from school to appeal to the state legislature and Gov. Dennis Daugaard — speaking out against a bill that could affect him and other transgender students.

Lewis was born a girl, but says he began to identify more as a boy when he was about 4 years old. He now lives openly as a boy, with the support of his family and friends.

He’s hoping to persuade Daugaard to reject a proposed measure that would restrict the use of school restrooms and locker rooms to students of the same biological sex, meaning transgender students would have to use the restroom of the sex they were born with, not the one with which they identify now.

The legislation — which passed the South Dakota Senate last week by a 20-15 vote — says that students who don’t identify as their biological gender may not use facilities designated for students of the opposite sex when those students might be present. Transgender students will instead be provided with a “reasonable accommodation” — defined in the proposal as the use of “a single-occupancy restroom, a unisex restroom, or the controlled use of a restroom, locker room, or shower room that is designated for use by faculty.”

It also orders that no “undue hardship” be placed on a school district — possibly referring to the construction of separate restrooms — and explains that private schools are exempt from the “reasonable accommodation” clause.