NASHVILLE, Tenn. (AP) — Republicans in several Southern states pressed ahead with an aggressive election-year redistricting effort Wednesday, undeterred by demonstrations and objections to their plans to reshape majority-Black congressional districts that have suddenly become vulnerable because of a U.S. Supreme Court ruling.

In Tennessee, protesters repeatedly interrupted legislative hearings on the redistricting plans, yet Republicans advanced them for a potential final vote Thursday.

WATCH: New wave of Southern states scramble to redraw congressional maps ahead of midterms

Despite passionate pleas from Black Democratic lawmakers, Republicans in the Alabama House approved a measure to upend the state's congressional primaries if courts allow them to switch their U.S. House districts. In South Carolina, Democrats chided Republican colleagues for abiding by President Donald Trump's desires as they took initial steps toward redrawing a district long held by a Black Democratic lawmaker.

The stakes are high for minority voters who stand to lose their preferred representatives and for any Republican lawmakers reluctant to follow Trump's wishes. In Republican primary elections Tuesday, Trump-endorsed challengers defeated at least five of the seven Indiana state lawmakers targeted by the president's allies for refusing to support a congressional redistricting effort last year.

The Supreme Court ruled last week that Louisiana relied too heavily on race when creating a second Black-majority House district as it attempted to comply with the Voting Rights Act. The ruling significantly altered a decades-old understanding of the law, giving Republicans in Louisiana and elsewhere grounds to try to eliminate majority-Black districts that have elected Democrats.

The ruling intensified an already fierce national redistricting battle ahead of a November midterm election that will determine control of the closely divided House.

Since Trump prodded Texas to redraw its U.S. House districts last year, eight states have adopted new congressional districts. From that, Republicans think they could gain as many as 13 seats while Democrats think they could gain up to 10. But some of the new districts could be competitive in November, meaning the parties may not get all they sought.

Tennessee plan splits up Memphis district

Republicans on Wednesday proposed a new U.S. House map that would split Memphis' home of Shelby County into three districts, instead of the current two. The map would break up Tennessee's lone Democratic-held district, centered on the majority-Black city, creating a ripple effect of alterations to districts throughout the western and central parts of the state.

"Tennessee is a conservative state, and our congressional delegation should reflect that. This bill ensures it does," Republican state Sen. John Stevens said.

READ MORE: Alabama and Tennessee governors have called special legislative sessions to draw new congressional districts

Republican House Speaker Cameron Sexton said the proposed districts were drawn based on population and politics, not racial data.

To adopt new House districts, Tennessee lawmakers also are seeking to repeal a state law prohibiting mid-decade redistricting.

Democrats and civil rights activists denounced the efforts during Wednesday's committee hearings.

The proposal "is Black vote dilution at an industrial scale," said Sekou Franklin, a political science professor at Middle Tennessee State University who is part of the Tennessee branch of the NAACP.

Protesters interrupted a Senate committee meeting, loudly chanting "Hands off our vote!" After senators suspended the hearing, state troopers cleared people from the room. Senators resumed their work elsewhere, advancing the legislation.

Later Wednesday, protesters in the hallway beat on the walls and doors of a committee room where senators were meeting. A House committee also paused its work as state troopers escorted chanting protesters from the room.

The candidate qualifying period in Tennessee ended in March, but legislation would reopen it to allow new candidates to join the races and existing candidates to switch districts. The primary election is Aug. 6.

Democrats noted that the state Supreme Court in April 2022 rejected a challenge to the current congressional map, finding it was too close to the election to make changes. This year, there's even less time before the primary elections, raising the potential of confusion for both candidates and voters, Democrats said.

Alabama House backs a new primary

The Republican-led Alabama House on Wednesday passed legislation authorizing special congressional primaries as Republicans eye the possibility of getting a different congressional map in place for the November elections. The bill now moves to the state Senate.

Alabama is seeking to lift a federal court order that created a second congressional district with a near-majority of Black voters. That map led to the 2024 election of Rep. Shomari Figures, a Black Democrat. Republicans want instead to use a 2023 map drawn by state lawmakers that would give the GOP an opportunity to reclaim Figures' south Alabama district.

The legislation won House approval on a party-line vote after four hours of fiery debate during which Black legislators said the moment calls back to the state's shameful Jim Crow-era history.

"It's a tragic step backward for Black Alabama voters. But we've been here before, and we will not give up this fight," Democratic state Rep. Adline Clarke said.

Democratic state Rep. Juandalynn Givan likened the legislation to poll taxes and counting jelly beans in a jar — a virtually impossible task that was used to suppress Black voters during the Jim Crow era.

"It is a calculated political maneuver born out of fear, a fear that is of Black people and most importantly Black political power," Givan said.

Tensions rose later Wednesday as dozens of protesters temporarily blocked a hallway outside the Senate, singing "We Shall Overcome" and shouting "we're not going back" as security officers tried to get them to leave.

Alabama's legislation hinges on the U.S. Supreme Court or a district court agreeing to lift the injunction.

"We're going to be ready if the court hands down a favorable ruling," said Republican state Rep. Chris Pringle, who sponsored the bill.

Alabama's primaries are May 19. If a court grants the state's request, the legislation would ignore the results for congressional seats and direct the governor to schedule a new primary under the revised districts.

South Carolina to test its will for redistricting

Democratic U.S. Rep. Jim Clyburn has represented South Carolina's 6th Congressional District since it was redrawn in 1992 to favor minority voters. He's running for an 18th term. But winning reelection could be harder for him if Republicans redraw his district.

A committee on Wednesday easily passed a proposal that could allow South Carolina lawmakers to consider drawing new congressional districts, setting up a showdown on the House floor later in the day.

The resolution would require a two-thirds vote to pass. Republicans have a supermajority, but some are concerned that an attempt to redraw the map to eliminate the state's lone Democratic representative could backfire and create up to two districts where Democrats are competitive.

Democratic state Rep. Spencer Wetmore said the redistricting effort reveals cynical politics focused more on winning for a narrow group than on helping all people.

"Daddy Trump calls and needs to grasp at some power, and once again we jump," she said.

The state's primaries are June 9, and early voting starts in three weeks.

Chandler reported from Montgomery, Alabama; Collins from Columbia, South Carolina; and Lieb from Jefferson City, Missouri. Associated Press reporter Kristen M. Hall contributed.