MADISON, Wis. (AP) — Wisconsin voters with disabilities should be able to cast their ballots electronically and failure to provide that option for the upcoming Aug. 13 primary and November presidential election is discriminatory and unconstitutional, a lawsuit filed Tuesday in the battleground state alleges.

The lawsuit seeks to require that electronic absentee voting be an option for people with disabilities, just as it is for military and overseas voters. Under current Wisconsin law, people with disabilities are “treated unequally and face real and considerable hurdles to participating in absentee voting,” the lawsuit argues.

Absentee ballots, including who can return them and where, have been a political flashpoint in swing state Wisconsin, where four of the past six presidential elections have been decided by less than a percentage point. The Wisconsin Supreme Court is scheduled to hear arguments next month in a case seeking to overturn a previous ruling banning absentee ballot drop boxes.