Maine looks to become the latest state to embrace an increasingly popular initiative for boosting turnout in elections: automatic voter registration.

The Democratic-majority state Senate voted, 19-14 along party lines, for its own so-called AVR bill on Monday. As soon as Wednesday afternoon the senators were expected to cast an identical vote for similar legislation approved last week in the Democratic state House. After a budgetary review, the bill would go to Democratic Gov. Janet Mills for her expected signature.

Under the bill, starting in January 2022, eligible Mainers who have not registered in their municipalities would be automatically added to the voter rolls when doing business with the motor vehicle bureau or another agency that collects similar information – unless they ask to opt out.

Republicans in Augusta have been united in opposition to AVR. The conservative Maine Heritage Policy Center says it would open elections to "potential fraud and abuse," citing California's mistaken addition of hundreds of voters to the rolls last year.

Seventeen states and the District of Columbia have adopted automatic voter registration in time for the 2020 presidential election.

The liberal-leaning Brennan Center for Justice, which promotes easier ballot access, says that in each state where AVR has been in effect for a while, registration has increased well above what it would have been otherwise. The biggest gain was in Georgia, where between 2014 and last fall the rolls swelled to almost 7 million from 6 million — what the center calculated as a 94 percent increase above what would have happened without automatic registration.