We knew the so-called Protect North Carolina Workers Act, signed by the governor last month, would be bad for immigrants. It could be bad for U.S. citizens too—specifically, children.

Research from children and families advocacy groups NC Child and First Focus estimates that the new law could harm more than 170,000 U.S. citizen children from mixed-status families living in North Carolina, by threatening their access to education and other critical services. According to the Migration Policy Institute, North Carolina is currently home to 750,000 immigrants, including nearly 350,000 undocumented immigrants.

The law prohibits immigrants from using consular documents (like the Mexican-government issued matriculas) as well as municipal and organizational IDs to identify themselves to justices, clerks, magistrates, police officers and “other government officials.” NC Child and First Focus say that the language of the legislation—specifically the inclusion of “other government officials—” is too broad, and could be interpreted to include educators, social workers, health care and other kinds of service providers.

“Without valid identification, parents may face challenges in enrolling their children in school, obtaining birth certificates, and accessing other critical services on behalf of their children,” said a joint statement from NC Child and First Focus.

In some North Carolina school districts, parents are required to provide photo identification when enrolling their children in school.

The study points to Texas, where prohibiting the use of the matricula consular to establish identity has meant that families have been unable to obtain a birth certificate for their children born in the state. Without a birth certificate, these families have faced difficulties enrolling their children in public schools and establishing their eligibility for programs like Medicaid.

“Family values are American values, and we have been calling on policymakers to consider the impact of their decisions on children and parents,” said Bruce Lesley, president of First Focus. “But children continue to be an afterthought in immigration policies like this that devalue them and ignore their best interests. [This law] is a perfectly horrible example of how misguided policy can have dire consequences on the basic rights of our children to obtain their birth certificates, receive an education and access health care.”

“Each individual arriving here in a legal manner, following our laws in search of a better life, is a blessing to our state and a blessing to our country,” Gov. McCrory said in a statement. “We want to continue that strength of our great country, but in doing so we all must follow the law.”