The latest suit means that about half of all states are now battling the administration over the culturally divisive issue of transgender students and whether they should be permitted to use the restrooms of their choice. The growing number of lawsuits makes it all but inevitable the transgender rights issue will make its way to the Supreme Court.

The newest states to join the fray are Arkansas, Kansas, Michigan, Montana, Nebraska, North Dakota, Ohio, South Carolina, South Dakota and Wyoming. Their lawsuit was filed in federal district court in Nebraska.

The lawsuits follow a May directive from the Education and Justice Departments saying that transgender students must be afforded sweeping civil rights protections under Title IX, the federal law prohibiting sex-based discrimination in educational programs and activities. That includes their right to use bathrooms and locker rooms that align with their gender identities.

The Obama administration has threatened to withhold federal funding over the issue, but has yet to do so. The filing says the Nebraska Department of Education is expected to receive $332 million in federal funding for fiscal year 2016-17 -- $312 million of which will go to local school districts.

Critics’ chief argument is that the Obama administration is rewriting the definition of “sex” in “sex-based discrimination” to include gender identity. Legal scholars have said it will take the Supreme Court or an act of Congress to make clear that gender identity is protected by federal civil rights laws.

“Current state law and federal regulations allow schools to maintain separate facilities based upon sex,” Nebraska Attorney General Doug Peterson said in a statement. “The recent action by these two federal agencies to require showers, locker rooms, and bathrooms be open to both sexes based solely on the student’s choice, circumvents this established law by ignoring the appropriate legislative process necessary to change such a law. It also supersedes local school districts’ authority to address student issues on an individualized, professional and private basis.”

But Joshua Block, an attorney with the ACLU Lesbian Gay Bisexual and Transgender Project, said the lawsuits are purely political, noting the administration’s directive is non-binding.

“Disagreeing with the Obama administration’s interpretation of the law doesn’t give them standing to sue over it,” he said.

The Education Department has put out nonbinding guidance on other issues, including racial disparities in school discipline, colleges’ handling of sexual assault and protecting civil rights in juvenile justice facilities.

Republicans, though, have seized on that guidance — meant to clarify the Obama administration’s position and offer best practices — as imposing federal mandates and unlawfully subverting Congress.

Friday’s lawsuit was filed against the Education Department, Justice Department, the Equal Employment Opportunity Commission and the Labor Department.

The Obama administration has also said that transgender individuals are protected under Title VII, which prohibits sex-based discrimination in employment.

Thirteen other states — Alabama, Arizona, Georgia, Kentucky, Louisiana, Maine, Mississippi, Oklahoma, Tennessee, Texas, Utah, West Virginia and Wisconsin — filed a brief in federal court earlier this week to stop the Obama administration from enforcing its interpretation of the laws. The case was first filed in May by 11 states in federal district court in Texas.

North Carolina has its own separate legal standoff with the Justice Department over that state’s so-called bathroom law, which requires transgender students to use a bathroom that aligns with the gender listed on their birth certificate. The state and the agency have filed dueling lawsuits.

The Human Rights Campaign said Friday that 68 companies have signed onto a brief in support of the Justice Department’s lawsuit to dismantle the North Carolina law, HB2.

The highest court to tackle the issue of transgender student rights so far is the U.S. Court of Appeals for the Fourth Circuit, which earlier this year upheld a Virginia transgender teen’s right to use the boy’s bathroom at his high school.

The school board in that lawsuit, Gloucester County School Board, plans to ask the Supreme Court to review its case.

The Justice Department declined to comment due to pending litigation.