The Virginia Supreme Court on Friday struck down a voter-approved Democratic congressional redistricting plan, delivering another major setback to the party in a nationwide battle against Republicans for an edge in this year's midterm elections.

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The court ruled that the state's Democratic-led legislature violated procedural requirements when it placed the constitutional amendment on the ballot to authorize the mid-decade redistricting. Voters narrowly approved the amendment April 21, but the court's ruling renders the results of that vote meaningless.

"This violation irreparably undermines the integrity of the resulting referendum vote and renders it null and void," the court said in its opinion.

Democrats had hoped to win as many as four additional U.S. House seats under Virginia's redrawn U.S. House map as part of an attempt to offset Republican redistricting done elsewhere at the urging of President Donald Trump. That ruling, combined with a recent U.S. Supreme Court decision severely weakening the Voting Rights Act, has supercharged the Republicans' congressional gerrymandering advantage heading into this year's midterm elections.

Legislative voting districts typically are redrawn once a decade after each census to account for population changes. But Trump started an unusual flurry of mid-decade redistricting last year when he encouraged Republican officials in Texas to redraw districts in a bid to win several additional U.S. House seats and hold on to their party's narrow majority in the midterm elections.

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California responded with new voter-approved districts drawn to Democrats' advantage, and Utah's top court imposed a new congressional map that also helps Democrats. Meanwhile, Republicans stand to gain from new House districts passed in Florida, Missouri, North Carolina, Ohio and Tennessee. They could add even more after the U.S. Supreme Court's ruling in the Voting Rights Act case, which has prompted some other Republican states to consider redrawing their maps in time for this year's elections.

Virginia currently is represented in the U.S. House by six Democrats and five Republicans who were elected from districts imposed by a court after a bipartisan redistricting commission failed to agree on a map after the 2020 census. The new districts could have given Democrats an improved chance to win all but one of the state's 11 congressional seats.

Under the Demcoratic-drawn map, five districts would have been anchored in the Democratic stronghold of northern Virginia, including one stretching out like a lobster to consume Republican-leaning rural areas. Revisions to four other districts across Richmond, southern Virginia and Hampton Roads would have diluted the voting power of conservative blocs in those areas. And a reshaped district in parts of western Virginia would have lumped together three Democratic-leaning college towns to offset other Republican voters.

READ MORE: Southern Republicans press ahead with election-year House redistricting despite protests

The state Supreme Court's seven justices are appointed by the state legislature, which has toggled back and forth between Democratic, Republican and split control over recent years. Legal experts say the body doesn't have a set ideological profile.

The case before the court focused not on the shape of the new districts but rather on the process the General Assembly used to authorize them.

Because the state's redistricting commission was established by a voter-approved constitutional amendment, lawmakers had to propose an amendment to redraw the districts. That required approval of a resolution in two separate legislative sessions, with a state election sandwiched in between, to place the amendment on the ballot.

The legislature's initial approval of the amendment occurred last October — while early voting was underway but before it concluded on the day of the general election. The legislature's second vote on the amendment occurred after a new legislative session began in January. Lawmakers also approved a separate bill in February laying out the new districts, subject to voter approval of the constitutional amendment.

Judicial arguments focused on whether the legislature's initial approval of the amendment came too late, because early voting already had begun for the 2025 general election.

Attorney Matthew Seligman, who defended the legislature, argued that the "election" should be defined narrowly to mean the Tuesday of the general election. In that case, the legislature's first vote on the redistricting amendment occurred before the election and was constitutional, he told judges.

An attorney for the plaintiffs, Thomas McCarthy, argued that an "election" should be interpreted to cover the entire period during which people can cast ballots, which lasts several weeks in Virginia. If that's the case, he told justices, then the legislature's initial endorsement of the redistricting amendment came too late to comply with the state constitution.

In January, a judge in rural Tazewell County, in southwestern Virginia, ruled that lawmakers failed to follow their own rules for adding the redistricting amendment to a special session last fall. Circuit Judge Jack Hurley Jr. also ruled that lawmakers failed to initially approve the amendment before the public began voting in last year's general election and that the state had failed to publish the amendment three months before the election, as required by law. As a result, he said, the amendment is invalid and void.

The Virginia Supreme Court placed Hurley's order on hold and allowed the redistricting vote to proceed before hearing arguments on the case.