A border fence outside Brownsville, Texas. According to a lawsuit, the state has “acted with the intent to discriminate against Texas-born children on the basis of their parent’s immigration status.” Photograph by Shannon Stapleton//Reuters via LANDOV

Last month, Maria Isabel Perales Serna, an undocumented Mexican immigrant who’s lived in Texas for the past fourteen years, risked deportation to give a signed and sworn statement as part of a lawsuit against the state. Perales’s daughter was born last year in McAllen, Texas, but when Perales went to the Department of State Health Services to obtain a birth certificate she was turned away. (In Texas, hospitals issue a provisional document, and Health Services provides the birth certificate.) No one disputed her daughter’s legal status. The problem was that Perales herself did not have proof of identity the state would accept. Now her child is an American citizen without the papers to prove it. Hundreds, possibly thousands, of other parents across Texas are in the same bind. “I worry that, one of these days, they might think my daughter isn’t mine, and that they could separate me from my baby,” Perales said. “If someone kidnaps my daughter, what am I going to do without papers to prove that I am her mother?”

The denial of a birth certificate can have serious consequences. One mother involved in the lawsuit testified that, without her child’s birth certificate, her family no longer qualified for public housing. “The rent is now almost triple what it was before,” she said. The same was true for Medicaid. “How will I take care of the baby then, if he gets sick?” she asked. Another mother had to fight to get her son enrolled in the public school system. “They said that if we did not present his birth certificate within thirty days they would expel him,” she reported. One American child is stuck in Reynosa, a violent Mexican border town. Without a birth certificate (and, in turn, a passport), he is unable to return.

Birthright citizenship has come under fire this year from Republican Presidential candidates, egged on by Donald Trump. (Amy Davidson wrote about the issue this week.) Texas hasn’t denied the citizenship of these children, but it has effectively stripped away the rights that would go along with it. “Because of Trump, this is turning into a birthright-citizenship case, but that’s not what it is or ever was; not even the state can question whether or not these children are American citizens,” Efrén Olivares, a lawyer representing the mothers, told me. Joaquín Castro, a Democrat who represents San Antonio in congress, and who spent a decade in the Texas Legislature, said that the denial of birth certificates reminded him of the voter-I.D. laws that have passed in Texas and other states in recent years. “It’s mostly about putting up obstacles and creating impediments,” he told me. According to the lawsuit, which was filed by Texas Rio Grande Legal Aid and the South Texas Civil Rights Project, the state has “acted with the intent to discriminate against the Texas-born children on the basis of their parent’s immigration status, depriving the children of the rights, benefits, and privileges granted to all other citizen children.”

The problem turns on the matr__ícula consular, an identity card issued by the Mexican Consulate which is overwhelmingly used by undocumented immigrants. In Texas, the parents of an American-born child have to produce identification in order to secure a birth certificate. The list of acceptable documents includes a foreign or American driver’s license, an electoral card, and a national identity card. For undocumented parents, who may have lost everything en route to the U.S., most of these papers have either been stolen, lost, or expired, or else are impossible to get, making the matr__ícula their only option. (They could, in theory, have a foreign passport, but it would need an up-to-date American visa to be valid.)

For years, local registrars accepted the matr__ícula without incident, according to country clerks and lawyers across the state. In 2008, Texas officials wrote a letter to the Mexican Consulate in Austin, saying that the matr__ícula would no longer be accepted as proof of identity. (The official reason was concern that the matr__ícula could be used in identity theft. The Mexican government has since taken measures to improve the document’s security, but they have not influenced state policy.) Even so, local offices continued to exercise their own discretion, accepting matr__ículas and dispensing birth certificates.

Then, in 2013, immigration lawyers in South Texas started hearing from undocumented immigrants that their matr__ículas were being rejected. “These parents were one-hundred-per-cent shut out,” Jennifer Harbury, a lawyer with Texas Rio Grande Legal Aid, said. Health Services had begun to enforce a wider crackdown on matr__ículas. A Health Services official later told lawyers that the policy “was changed to keep undocumented persons from gaining legal status in this country.” The reports of rejected matr__ículas had started in the Rio Grande Valley, in South Texas, but soon they were coming from as far west as El Paso.

The timing was suggestive. Tens of thousands of unaccompanied children were streaming across the U.S. border from Central America in what President Obama called a “humanitarian crisis.” By the end of last summer, the number of children crossing the border alone had surpassed fifty thousand. The resulting strain on the immigration system led to an infusion of federal money to help shelter and process the children. It also gave rise to nativist conspiracy theories. Rick Perry, the Governor of Texas at the time, suggested that Democrats had somehow helped the children over the border. “How do you move that many people from Central America across Mexico and into the United States without there being a fairly coördinated effort?” he told a news program in June, 2014.

This spring, Texas Rio Grande Legal Aid and the South Texas Civil Rights Project filed their lawsuit against the state, representing four families: six children and four parents. “We thought, O.K., they’re going to give us the birth certificates for these kids, then quietly dismiss the case,” Efrén Olivares said. Instead, Texas fought back. The Attorney General’s office, which is representing the Department of State Health Services, requested that the suit be dismissed, invoking the sovereign-immunity provision of the Eleventh Amendment. Over the summer, twenty-one more families joined the lawsuit, and last month the Mexican government filed an amicus brief in support of the plaintiffs, who are requesting an emergency injunction to force the state to allow two forms of identity documents to be used in place of the matr__ículas. “Our argument isn’t: yes matr__ícula, no matr__ícula,” Harbury told the Texas Tribune. “The argument is: What will you take that people can actually get? They have to take something. [The children] were born here. They are American citizens.” A hearing before a federal judge is scheduled for October 2nd.

The state’s decision to opt for a protracted legal battle over the use of the matr__ícula has raised questions about its intentions in the case. “It’s been brought to the attention of everyone who could possibly resolve the situation—even if it was flying under the radar before—and yet it doesn’t get resolved,” Denise Gilman, a law professor at the University of Texas, said. “This should be a no-brainer of a case that’s resolved quickly. That it hasn’t says something about reactions at high levels.” (The state has maintained that some of these birth certificates exist on file but cannot be given out without the proper documentation from parents.)