RICHMOND, Va. (AP) — Virginia lawmakers approved a sweeping overhaul Saturday of how legislative and congressional maps are drawn, despite strong objections from some black legislators. The House and Senate approved a proposed constitutional amendment that would create a new commission empowered to draw legislative and congressional maps during the next redistricting process in 2021, a change from the current practice of lawmakers drawing the maps themselves. The measure must be approved again by the General Assembly next year, and then by voters, to take effect.

The 16-member commission would be a mix of lawmakers and citizens. Republicans and Democrats would be evenly split among the lawmakers and the citizen members would pick by retired judges from a list drawn up by lawmakers. A supermajority of both citizen and lawmakers commission members would be needed to present a map to the General Assembly for consideration. The General Assembly would have to vote up or down on any proposed maps. In the event of a stalemate, the Virginia Supreme Court would draw the maps. Governors would have no role in the process. Under current law, governors have veto power over any map proposed by the legislature.

Advocates of redistricting reform hailed the proposal’s passage. “Although this bipartisan plan does not reflect every provision we urged in our original proposal, make no mistake: This reform will end partisan gerrymandering in Virginia,” said Brian Cannon, executive director of the advocacy group OneVirginia2021.

The measure passed unanimously in the state Senate, but many black lawmakers in the House of Delegates voted against it. Black lawmakers said the commission would dilute the influence of African-Americans in drawing the maps. “We have great concerns about having African-American representation for redistricting, and this doesn’t guarantee that,” said Del. Lamont Bagby, chairman of the Virginia Legislative Black Caucus.

Redistricting reform has long been a hot-button issue in Virginia politics, with Democrats often campaigning on the need for an independent commission. Republican House Speaker Kirk Cox earlier this year said he backed the formation of a commission after years of objecting to the idea. Cox said lengthy federal court battles over maps drawn during the 2011 redistricting lines prompted his change of heart. Democratic-led lawsuits led to a federal court redrawing the state’s congressional map and could lead to a new state House map.

A panel of judges has given final approval to a redrawn map for the Virginia House of Delegates in a protracted racial gerrymandering case.

A federal panel of judges gave final approval to a redrawn House map earlier this month after a previous ruling that lawmakers had racially gerrymandered eleven districts by packing black voters into them.

Republicans are appealing the case to the U.S. Supreme Court. Arguments are scheduled for next month.