FALLS CHURCH, Va. (AP) — Virginia voters on Tuesday approved a referendum that puts redistricting next year in the hands of a bipartisan commission.

The amendment to the state constitution caps a yearslong effort by reformers looking to end partisan gerrymandering.

A bipartisan commission of citizens and legislators equally divided between Democrats and Republicans will now redraw the state’s congressional and General Assembly districts to conform with the 2020 Census.

Beginning with the 2021 redistricting, the amendment turns over the task of drawing state and congressional maps to a 16-member panel of eight legislators and eight citizens, evenly divided between Democrats and Republicans. The eight citizens will be chosen by judges from a list prepared by legislators.

The maps developed by the panel will be sent to the General Assembly for an up-or-down vote with no opportunity to amend them. If the maps are rejected, the Supreme Court of Virginia will draw them.

Reform proponents Brian Cannon, Wyatt Durrette and Bobby Vassar with the advocacy group FairMapsVA, issued a joint statement calling the vote “historic.”

“Virginia voters spoke loud and clear in approving Amendment 1,” they said. “In creating a bipartisan redistricting commission, they said they want a seat at the table when district lines are drawn next year and beyond. They said they want a transparent redistricting process. They want civil rights protections to be added to the state constitution for the very first time. And they said that they want to end partisan gerrymandering in Virginia once and for all.”

Some Democrats had tried to defeat the measure, arguing that the changes kept politicians too involved in the process. Republicans said Democrats were simply trying to preserve the status quo now that they’re in power so they could draw the lines to their own advantage.

With so much focus on the presidential race, many voters were unaware of the referendum. Indeed, first-time voter Michelle Shreve, 42, a restaurant manager from Falls Church, said she was confounded when she saw the referendum on the back page of her ballot. She relied on the Democratic sample ballot handed to her at her polling place Tuesday, which urged a ‘no’ vote.

Redistricting reform has become a hot-button issue nationally. Reformers say the practice of gerrymandering has led to anti-competitive legislative districts that choose polarizing candidates incapable of working across party lines in Washington and in state capitals across the country.

Still, Virginia was the only state where reformers were able to get a referendum in front of voters that allowed them to change the redistricting process. Advocates say efforts in other states, including Arkansas, Oklahoma, Oregon and Nevada, failed, in part because the coronavirus epidemic stymied the ability to collect petition signatures.