From the Michigan lawsuit referred to in my comment, I note this paragraph of their complaint might well have pertinence to the Wisconsin AG's dirt-dealing:

29.  Federal law provides substantial protection to prevent voters from being removed from rolls of registered voters as an election is approaching. The National Voter Registration Act, 42 U.S.C. § 1973gg-6, prohibits States from engaging in any effort to systematically remove voters from the list of eligible voters unless that effort was i) was completed more than 90 days before the date of the federal election and ii) is uniform (i.e., applied to everyone in the jurisdiction), non-discriminatory, and in compliance with the Voting Rights Act of 1965. 42 U.S.C. § 1977gg-6. Through the mass, systematic "lose your home, lose your vote" challenge process, Defendant Republicans are trying to do what federal law expressly prohibits state election officials from doing (even if they were to do it in a neutral and non-discriminatory fashion, which this is not): purge the voter rolls of voters on election day itself, thereby infringing on their ability to cast a ballot for federal office.