From the article:
“Flanagan determined Wisconsin’s voter ID law was the most restrictive in the country based on testimony from Ken Mayer, a University of Wisconsin-Madison political science professor. Mayer has estimated there are more than 220,000 Wisconsin residents who do not have photo IDs but who are otherwise qualified to vote.”
From here: http://gab.wi.gov/elections-voting/statistics
Wisconsin has 3,493,711 registered voters. 6.3% of those voters are registered, but don’t have IDs.
From here: http://gab.wi.gov/elections-voting/voters/registration-voting
Proof of Residence
The following constitute acceptable Proof-of-Residence if the document contains your current name and address and is valid on Election Day (unless otherwise indicated):
A current and valid Wisconsin driver license.
A current and valid Wisconsin identification card.
Any other official identification card or license issued by a Wisconsin governmental body or unit.
Any identification card issued by an employer in the normal course of business and bearing a photo of the card holder, but not including a business card.
A real estate tax bill or receipt for the current year or the year preceding the date of the election.
A residential lease which is effective for a period that includes election day (NOT for first-time voters registering by mail).
A university, college or technical institute identification card (must include photo), ONLY if the bearer provides a fee receipt dated within the last nine months or the institution provides a certified housing list to the municipal clerk.
A gas, electric or telephone service statement (utility bill) for the period commencing not earlier than 90 days before election day.
Bank statement.
Paycheck.
A check or other document issued by a unit of government.