Milwaukee’s voucher system, which allows low-income students to attend private schools using tax dollars, discriminates based on disability, according to a complaint filed Tuesday by the American Civil Liberties Union, the ACLU of Wisconsin Foundation and Disability Rights Wisconsin, the Huffington Post reports. The complaint seeks an investigation into the system, which the groups allege segregates Milwaukee students, and expresses the desire to end the alleged discrimination, halt efforts to expand the system until the discrimination is fixed and mandate better oversight…