PIERRE >> South Dakota’s governor vetoed a bill that would have made the state the first in the U.S. to approve a law requiring transgender students to use bathrooms and locker rooms that match their sex at birth.

Republican Gov. Dennis Daugaard, who initially reacted positively to the proposal but said he needed to research the issue, rejected the bill Tuesday after groups such as the American Civil Liberties Union and the Human Rights Campaign insisted it was discriminatory.

In his veto message, Daugaard said the bill “does not address any pressing issue” and that such decisions were best left to local school officials. He also noted that signing the bill could create costly liability issues for schools and the state. The ACLU had promised to encourage legal action if the bill became law.

“I am so happy right now. You have no idea,” said 18-year-old Thomas Lewis, a transgender high school student in Sioux Falls. Lewis said he has support at his school, but that the veto shows such support goes beyond his friends.

“The government’s not going to hold me back from who I really am,” he said.

The bill’s sponsor, Republican Rep. Fred Deutsch, said he would ask lawmakers not to override the veto, saying more focus on the issue would detract from the Legislature’s other accomplishments this year. The Republican-controlled Legislature approved the bill last month, with supporters saying it would protect student privacy.

Transgender rights have become a new flashpoint in the nation’s cultural clashes following the landmark U.S. Supreme Court ruling that legalized same-sex marriage last year. The high court victory encouraged advocates for lesbian, gay, bisexual, and transgender rights to push harder, prompting backlash from conservatives.

Caitlyn Jenner, the transgender activist and former Olympic decathlon gold medalist, had called on Daugaard to veto the bill. Opponents also used the South Dakota Tourism Department’s Twitter hashtag to take aim at the state’s roughly $3.8 billion tourism industry.

Other high-profile cases include last week’s vote in North Carolina by the Charlotte City Council to allow transgender people to choose a bathroom. The vote was immediately criticized by Gov. Pat McCrory, who said it denied privacy rights for those who expect to share restrooms or locker rooms only with people born with the same anatomy.

In Texas, Houston voters soundly defeated an ordinance that would have banned discrimination against transgender people after opponents alleged it would allow sexual predators to go into women’s bathrooms.

Daugaard initially offered a positive reaction to South Dakota’s proposal, but said he wanted to listen to testimony before making a decision. Last week, he met with three transgender individuals and heard their personal stories; before the meeting, the governor said he had never knowingly met a transgender person.

Opponents said the legislation was an attack on vulnerable transgender students that would further marginalize them at school. They also criticized comments made by some lawmakers, including Republican Sen. David Omdahl.

“I’m sorry if you’re so twisted you don’t know who you are,” Omdahl said when asked about the bill last month. “I’m telling you right now, it’s about protecting the kids, and I don’t even understand where our society is these days.”

Under the plan, schools would have been required to provide a “reasonable accommodation” for transgender students, such as a single-occupancy bathroom or the “controlled use” of a staff-designated restroom, locker room or shower room.

Supporters said the proposal was a response to changes in President Barack Obama administration’s interpretation of the federal Title IX anti-discrimination law related to education. Federal officials have said barring students from restrooms that match their gender identity is prohibited under Title IX.

Deutsch had said the plan pushed back “against federal overreach and intrusion into our lives.”

Heather Smith, executive director of the ACLU of South Dakota, said Tuesday that had the governor signed the bill, schools would have been forced to choose whether follow state or federal law. She also said her organization would have encouraged any student harmed by the new law to file a federal civil rights complaint.

Smith said people from across the state and country reached out to the governor to urge this veto. She said that’s the true testament of democracy.

Chad Griffin, president of the Human Rights Campaign, added that the governor “chose to do the right thing.”

“Today, the voices of fairness and equality prevailed, and these students’ rights and dignity prevailed against overwhelming odds and vicious opponents in the state Legislature,” Griffin said.

Lammers reported from Sioux Falls.