For three years, the Department of Justice (DOJ) has been investigating Wisconsin’s school voucher program for systematically discriminating against students with disabilities. The investigation began after Disability Rights Wisconsin and the American Civil Liberties Union, where I work, filed a complaint in June 2011 alleging that the state’s program was violating the rights of students with disabilities by excluding most of them.

Last year, DOJ issued a letter to Wisconsin state officials which informed them that its voucher program must comply with the Americans with Disabilities Act. In its letter, DOJ reminded Wisconsin that the state’s “obligation to eliminate discrimination against students with disabilities is not obviated by the fact that the schools participating in the program are private secular and religious schools.” The ADA covers Wisconsin, which has provided public funds to private schools participating in the voucher program. As a result, the state is obligated to eliminate discrimination against students with disabilities in its program.

For over 20 years, Wisconsin has been operating the country’s oldest voucher or “school choice” program in Milwaukee. In the last few years, vouchers have been expanded to other Wisconsin cities. Very few students with disabilities in Milwaukee or the rest of the state use private school vouchers, either because they perceive that the program is only for non-disabled students or because the schools themselves push children with disabilities out of the program. This has had the effect of segregating students with disabilities in the local public schools, while cannibalizing the local district’s resources through the diversion of money from public schools to private institutions.

School voucher programs like the one in Wisconsin and similar programs around the country, like tax credits for private school tuition, do not provide a choice for everyone. But DOJ’s ongoing investigation of Wisconsin and other state voucher programs is a step in the right direction of ensuring that states are not permitted to create a civil rights vacuum by abdicating public education to private schools.

Public schools must take all comers — including children with disabilities, those who are poor, and those who are more difficult to educate — because federal law requires that they not discriminate on the basis of race, color, national origin, sex, or disability. Voucher programs, on the other hand, attempt to skirt anti-discrimination laws and principles by alleging that so-called private schools are not subject to federal anti-discrimination laws, even though they take public money.

The exclusion of certain groups of children, such as children with disabilities, and students whose parents cannot afford the additional costs related to transportation and books from these programs is a disturbing precedent. And if — as is the case in Wisconsin — the exclusion of students with disabilities is something voucher programs wish to protect or ignore, who will be excluded next?

Essentially, the entire civil rights framework applicable to public school students —including the inclusion of students with disabilities, the integration of students of color, and the rights of those subject to discipline — is erased if we slip down this slope of permitting voucher schools to operate in a vacuum free of the restraint of federal civil rights laws, such as the ADA. We will have publicly-funded schools for our children that are completely free from public oversight designed to protect their federal civil rights.

Therefore, the stakes are high.

Milwaukee, after 20 years, is a great example of the fallacy of the argument that private schools participating in the state’s voucher program should be free from oversight. The students in most of the schools participating in Milwaukee’s voucher program are almost all receiving vouchers. When we filed our complaint in 2011, 83 percent of the student population at any given Milwaukee private voucher school attended with a publicly funded voucher. In 22 of those schools, we found that every single student’s education was paid for using a voucher. Let’s be clear here: Milwaukee’s voucher schools are private in name only.

This all raises a critical question: At what point does a private school that is operated with almost all public dollars become a public school, accountable to the parents of the children that it discriminates against? According to voucher supporters, there is no point where private schools — even if fully funded by public money — become accountable to the public.

In the latest of a series of deceptive characterizations of DOJ’s investigation of the Wisconsin voucher program, the explicitly pro-voucher Wisconsin Institute for Liberty and Law (WILL) published an article in the National Review entitled “Obama’s War on Vouchers Rolls On.” It follows articles last month reporting that eight Wisconsin legislators want to be updated about the DOJ inquiry, believing it represents a federal overreach into the state’s education system. WILL and the eight legislators are essentially making a tired states’ rights claim, recycled from the opponents of integrated schools fifty years ago. They argue that the federal government has no business telling Wisconsin what to do with its education system.

In their letter to the Department of Public Instruction demanding to be kept informed, the legislators complaining about the investigation conceded that private voucher schools “need to be held accountable.” They believe, however, that they “are doing that at the state level” and that allowing “the federal government to dictate state policy in this area is not the answer.” Following the legislators’ lead, WILL’s National Review article essentially frames any federal civil rights investigation of a voucher program as a “war on poor families” and that impacted states, such as Wisconsin and Louisiana, may “decide” this issue. Of course, with respect to a state’s violation of federal civil rights laws, that is completely inaccurate.

Federal civil rights laws are in place to ensure that states do not undermine the federal rights of marginalized groups, including people with disabilities, racial minorities, religious minorities, and women. So whether or not a state is discriminating against a group of people is not solely an issue for the state to decide, it is also an issue for the federal government to investigate and, if necessary, enforce. It’s very interesting that the mere federal investigation into whether or not discrimination exists is being met with opposition by some leaders in Wisconsin. Such strong protest at the mere investigation suggests to us that our complaint is valid.

Seventy-five percent of those applying for the vouchers in the expanded statewide program already attend private schools. The voucher program, which is designed to educate low-income students, has been hijacked as a means to subsidize tuition for families who have already left Wisconsin’s public schools.

Furthermore, the article also makes the specious claim that “the state has received no complaints of disability discrimination in the choice [voucher] program.” Of course they haven’t. For two decades, the state has had no complaint system in place and, therefore, no way of tracking complaints. It is, at best, misleading to suggest that parents of children with disabilities have not had any complaints regarding the program throughout its existence. At its worst, the statement denies the existence of our complaint and is patently false.

There are now over 20 states and the District of Columbia that use public funds to subsidize private school enrollment, whether it’s a tax credit for parents of students attending private schools or voucher programs, like the one in Wisconsin, that give a student a taxpayer-funded voucher worth a certain amount to pay private school tuition. These programs are touted as giving poor students, often in so-called “failing districts,” the same “choice” that wealthy students have. In Wisconsin and Indiana, these programs are springing up statewide and in public school districts that are not failing. The argument that these programs are an escape from failing school districts is rapidly falling apart as more and more programs are statewide and aimed at decreasing the tuition costs of students’ families who already can afford private schools.

As these public subsidies for private schools expand throughout the country, the civil rights umbrella available to public school students is at risk of folding. In some states like Georgia and Alabama, private schools benefiting from voucher or tax credit programs were founded as segregation academies to thwart federal integration efforts. While the program in Milwaukee and its school district serve almost entirely students of color, as “school choice” spreads around the country, the stage is set for these programs to become even more exclusionary and segregated. If states and local communities permit this to continue, they will cement the public funding of separate schools for only select groups of students, which evidence shows will disproportionately exclude racial minorities, students with disabilities, religious minorities, and LGBT students. This flies in the face of what we have known for the 60 years since Brown v. Board of Education — separate is not equal.

Even the WILL article acknowledges that DOJ wants to reform the program, not kill it. DOJ requests that the state boost its oversight of the program to ensure that it is not discriminatory. This seems harmless enough. Nevertheless, voucher supporters in Wisconsin say Washington has declared war on them when it’s clear the Justice Department only wants to ensure school privatization doesn’t undermine the hard-fought gains of educational equity in the places most historically resistant to it. The only logical conclusion from this response is that voucher supporters fear oversight and want to continue to operate in a civil rights vacuum.

If that is their fear, then we know what the true purpose of Wisconsin’s voucher program is. It is to create segregated school systems, both in terms of race and in terms of disability. The result is a public school district deprived of the resources to educate its students and left with those most difficult to educate.

Stopping this from getting even worse would be a war worth fighting.

Courtney Bowie is a senior staff attorney with the ACLU Racial Justice Program. Reprinted from Medium.com.