Missouri voters have approved amending the state Constitution to allow lawmakers to add voter-identification requirements at the ballot box.

At issue were longstanding efforts by Republicans to require voters to show government-issued photo ID, ostensibly to prevent voter fraud. Democrats countered that such a requirement could disenfranchise thousands of voters who don’t have a driver’s license or other identification.

The Missouri Supreme Court has ruled against photo-ID requirements in the past. That’s why lawmakers this year asked voters to change the constitution to give them the power to require a photo ID to vote.

Missouri lawmakers in September overrode Gov. Jay Nixon’s veto of a bill laying out which IDs qualify and requires the state to pay for individuals to obtain an ID or documents necessary to get an ID.