DENVER — In Texas, Lt. Gov. Dan Patrick urged school boards to ignore an Obama administration directive on the use of school bathrooms and locker rooms by transgender students. "We will not be blackmailed," he said, referring to the threat that schools could lose federal funding if they do not comply.
In New York City, the nation's largest public school district, officials welcomed the news, saying they had put similar policies in place in early 2014.
Hours after the Obama administration announced a new policy Friday that allows students to use the bathroom that matches their gender identity, the reaction was swift and sharp.
Patrick called it "the biggest issue facing families and schools in America since prayer was taken out of public schools."
For Chirlane McCray, the wife of Mayor Bill de Blasio of New York and co-chairwoman of a city commission on gender equality, said it was a case of basic human rights. "No child should face humiliation and embarrassment because of their gender identity, especially during such a private moment," she said.
Conservative politicians like Patrick warned of boys in the girls' locker room, and condemned what they called an illegal intrusion by the Obama administration that endangered schoolchildren.
Transgender students hailed a breakthrough for their rights, and said they were pleased to be able to use the school bathroom where they felt comfortable.
It is unclear how many students the new directive will affect. One estimate by transgender advocates said there are between 165,000 and 550,000 transgender students, or 0.3 percent to as many as 1 percent of the 55 million public and private school student population nationwide. That figure is based on a study by the Williams Institute at the University of California, Los Angeles, School of Law that estimated the adult transgender population at about 700,000, or 0.3 percent of the adult population of the United States.
The directive provoked polarized responses as it reverberated across America's culturally divided landscape Friday. It shined a wide new spotlight on an emotional debate surrounding transgender rights and public accommodations that has become the subject of contested votes and protests in places like Houston and North Carolina, and became political fodder in the presidential primary races.
Some politicians and advocates outraged by the directive suggested that they might challenge it in court. Ken Paxton, the attorney general of Texas, said President Barack Obama "better prepare for yet another legal fight." In Florida, the Liberty Counsel, a conservative legal group that litigated against same-sex marriage, offered to represent any school board that wanted to fight the administration on issues of gender and bathrooms.
Some school officials, and even some of the policy's supporters, said the directive could prove difficult to put in place and would do little to clarify the debate. Francisco Negron, the general counsel of the National School Boards Association, said the administration's letter "continues to reflect the fact that the law is at odds around the country," and clarity could only come from Congress or the courts.
Until then, some school board members, who are sworn to uphold state laws, "are placed in a position of having to pick your poison — to be out of compliance with the state law or with the federal law," Negron said. "We're dealing with a situation where the social norms are changing so rapidly that the legal framework has not caught up."
But among students, the response was far warmer. Many students interviewed across the country Friday said they wanted their transgender classmates to feel accepted and safe, and spoke of gender as a deeply personal — and in some cases, fluid — issue that is best treated with tolerance.
"I'm totally fine with it — it's who they are," said Valery Martinez, 14, as she stood outside Hamilton High School in Los Angeles.
But many adults expressed disapproval, reflecting a divide that is generational as well as geographic. Critics outside of big cities and blue states said that they felt Washington was telling them what to do about a fiercely contested issue that draws hundreds of people to school-board meetings, state legislative hearings and prayer vigils.
In Blue Ridge, Georgia, a sparsely populated area neighboring North Carolina and Tennessee, hundreds of people marched to a school board meeting on Thursday night to insist that the district stick to traditional, anatomical standards in defining sex.
Steve Fallin, a pastor who participated in the march, spoke of a rising anger among many Christians who feel they are not being treated with respect, a fury that intensified Friday with news of the president's directive.
"What President Obama did with this letter, he just cranked up the heat on the pot just a few degrees too high," Fallin said. "I can tell you from what I saw last night, most of rural America, particularly the South, is right ready to just boil over."
Patrick, the Texas lieutenant governor, put it in stark terms. "Parents are not going to send their 14-year-old daughters into the shower or bathroom with 14-year-old boys," he said. "It's not going to happen."
Even before Friday's announcement, some boards of education made pre-emptive efforts to pass policies relating to education and gender after watching the Obama administration intervene in scattered local cases, most recently with a lawsuit against North Carolina's law.
At a Thursday meeting of the Alabama State Board of Education, a board member, Matthew Brown, proposed a resolution that would establish "default policies" for the state's schools, restricting the use of bathrooms and athletic teams to students by "biological sex, as recorded on the student's birth certificate."
Conservative critics compared the administration's directive to Obama's executive actions on immigration or climate change, saying it had wrenched authority from local school boards and disregarded conservative cultural values.
"It's just an overreaching federal government that didn't follow the rules," said Nancy Stacy, a school board member in Marion County, Florida, which is facing a civil-rights complaint by the American Civil Liberties Union on the issue. "They're just bullying everybody."
The ACLU's Florida chapter said it had filed a federal complaint on behalf of a transgender male student in Marion County who was suspended for using the men's room at school. On Friday, the district said it would not change its bathroom policy, saying the administration's letter did not appear to be a binding presidential order. Stacy, the board member, said she believed that sex was determined by anatomy and chromosomes, "period."
"It's easy," she said. "Every student that comes to school and says 'I'm Cinderella' — should we give them a carriage to ride around in? Children have quite an imagination and this is an adult agenda that's being pushed."
But the directive won acclaim from advocates for transgender rights, as well as the largest teacher's union and the National PTA. Transgender students and their parents said that the directive was not surprising given the administration's stance on recent transgender rights cases, but they said it nonetheless was a milestone.
Capri Culpepper, a transgender high school senior in Anderson, South Carolina, said the guidelines offered support to students like her, who can feel isolated and ostracized. She said school officials told her last year that she had to stop using the girl's restroom because it was making people uncomfortable, and allowed her to use a staff bathroom or one in the nurse's office.
"They were segregating me into this restroom that I didn't feel like I belonged in," she said.
Kathryn Mathis' family fought one of the country's first public battles over bathroom access for a transgender child after her daughter, Coy, who was 6 years old at the time, was denied the use of the girl's bathroom at her Colorado school. Coy is now in the fourth grade at a new school that accepts her gender identity, and Mathis said she is happy and getting good grades.
"It's incredibly gratifying," Mathis said of Friday's directive. "Kids like Coy just want to be like other kids. They just want the dignity and respect."
But Jabari Lyles, president of a gay community center in Baltimore and the education manager for Baltimore's chapter of the Gay, Lesbian and Straight Education Network, who applauded the directive, said it would be an uphill battle to put in place.
"Hopefully, what this doesn't do is put transgender students more in danger because the law has taken a bold step on their side," he said.