Invoking Republicans’ phantom fear of voter fraud, Gov. Bruce Rauner has vetoed a bipartisan measure to make Illinois a pioneer in one of the truly innovative reforms of modern politics — the automatic registration of citizens as they conduct routine business at motor vehicle departments and other state agencies.

In the past 18 months, five states have approved this obvious boon for electoral democracy; others have it under consideration. The state sends proof of registration electronically to local election officials. Voters are thus spared the old bureaucratic paperwork maze and haphazard record-keeping that compounds delays on Election Day. Citizens are free to not register (and, of course, to not vote), but they cannot complain about opportunity denied.

More than 30 states have registration systems that require a voter to opt in at motor vehicle offices. That places the burden on voters. Automatic voter registration (A.V.R.) takes the process a step further, placing the responsibility on the state. As it is, the United States is one of the few democratic nations that place the registration burden on voters, leaving up to a third of eligible citizens unregistered. Canada’s automatic system has registered more than 90 percent of those eligible.

Had the Illinois measure gone forward, it would have added two million potential new voters to the rolls once it began in 2018. A more immediate effect would have been to update the registration of an estimated 700,000 voters in time for this November’s elections.