Ohio voters approved State Issue 3 on Tuesday, according to final unofficial results from the Ohio Secretary of State reported by Knox Pages.
The measure carried 65.88% of the vote to 34.12%, with 4,186,334 ballots counted on the question.
Issue 3 writes the state's current photo identification rule for in-person voting into the Ohio Constitution. It also sets ID requirements for other voting methods, including absentee voting.
Supporters have argued the change guards against future voter fraud. Fred Dailey, chairman of the Knox County Republican Party, previously told Knox Pages that Ohio's system compares well with other states and that he wants to preserve its integrity.
Placing the requirements in the constitution means future lawmakers cannot alter them through ordinary legislation, making changes more difficult.
Under the rules, voters at the polls must present approved photo identification. Accepted forms include a driver's license or state ID card, a U.S. passport or passport card, and military IDs, including Ohio National Guard cards and cards from the U.S. Department of Veterans Affairs or a successor agency.
Knox Pages also published county-level results for areas served by Source Media Properties and additional coverage explaining what the amendment changes.