In February 2016, Anita Johnson met a woman in Milwaukee fretting that, although she had voted faithfully for decades, she would be unable to cast a ballot in the presidential election.

Her Wisconsin driver’s license was about to expire, and since she was 90 and no longer drove, she wouldn’t renew it. But she had heard about the state’s strict new voter ID law, requiring official photo identification.

Without a license, she worried she was out of luck. Maybe not, said Ms. Johnson.

The state coordinator for VoteRiders, a nonprofit, nonpartisan organization that helps citizens vote, Ms. Johnson pointed out that the state Department of Motor Vehicles could issue a photo ID. Poll workers would accept that as proof of identity.

On the very last day the would-be voter had a valid license, Ms. Johnson drove her to the agency, which issued the necessary state card.