MONTGOMERY (AP) — Alabama lawmakers worked overnight as Republicans pushed toward a Thursday evening redistricting vote over the objections of Democrats.

The House of Representatives met until nearly 4 a.m. Thursday morning. Representatives planned to resume debate mid-morning after lawmakers get a few hours of sleep.

Republican Rep. Randy Davis, chairman of the redistricting committee, told lawmakers the proposed new lines address problems found by a federal court with Alabama’s current boundaries. Davis said it also complies with other redistricting decisions out of the U.S. Supreme Court.

Black Democrats argued the proposed new lines are designed to minimize the influence of black voters and entrench GOP dominance. While Republicans ultimately have the votes to approve the legislation, black lawmakers used delaying tactics to protest the plan.

“It’s clear you can look at the map. There is racial gerrymandering,” Legislative Caucus Chairman John Knight, D-Montgomery, said.

Both the House and Senate were expected to lockdown Thursday as black lawmakers planned to have the lengthy bills read aloud, a process expected to take more than eight hours.

Federal judges in January ordered lawmakers to redraw some lines before the 2018 elections. The ruling came after the Legislative Black Caucus and the Alabama Democratic Conference filed a lawsuit arguing African-American voters were “stacked and packed” into designated minority districts to make neighboring districts whiter and more Republican.

Partisan and racial control of Jefferson County, home to the state’s largest city, Birmingham, which is majority black, has been a major point of contention. The county is often the focus of partisan squabbles over legislation affecting local governments. The proposed new map would maintain a slim Republican majority in the Jefferson County delegation.