The Supreme Court handed Democrats a significant victory Thursday in Missouri's gerrymandering battle, blocking a GOP push to use a map likely to give Republicans another House seat.

Acting without any noted dissent, the high court granted an emergency appeal by redistricting opponents who recently persuaded the Missouri Supreme Court to mandate the use of existing district lines for the November election.

The state's primaries, held last month, used new, more GOP-friendly maps.

U.S. District Judge Stephen Clark, a Trump appointee, essentially overrode the Missouri Supreme Court earlier this week, ordering officials to use those new maps in the general election. The Supreme Court blocked Clark's order on Thursday, appearing to signal that federal courts should stay out of the dispute.

The justices' ruling hands a major win to Democrats, who fought nearly a dozen legal battles with Missouri Republicans over the legality of the GOP-led gerrymander.

Hoskins and other state officials had predicted chaos if they were forced to drop the redistricting plan at this point. Two GOP House candidates filed suit in federal court, complaining the districts they just ran in during the primaries had been effectively redrawn.

After the Missouri Supreme Court's decision, election officials shifted their plans to rely on the old maps — only for Clark, and then Hoskins, to tell them to switch to the new ones.The Supreme Court's action Thursday forces election officials in Missouri to make another late map switch, back to the old maps.

The justices' ruling came just minutes before the Missouri Supreme Court convened a hearing on whether to hold Missouri Secretary of State Denny Hoskins in contempt for defying its order to use the existing lines this fall.

Several members of Missouri's highest court expressed irritation with Hoskins during the 35-minute session — and the lawyer representing him seemed to exacerbate that irritation by refusing to firmly commit to using the old map in the wake of the U.S. Supreme Court's ruling.

"The secretary was truly in a rock in a hard place," William Seidleck, the state's principal deputy solicitor general, said in court. "The secretary acknowledges this court's injunction is back in full force and effect, and is evaluating next steps…Options are being carefully evaluated."

"I'm less than perfectly comfortable with your response that you were going to evaluate options going forward," Judge Paul Wilson said. "What else is there to be considered?"

Seidleck said he expected Hoskins to send new guidance to local officials soon, but he also noted that the suit filed by the two GOP candidates is still pending.

"I thought we were all going to agree to be adults here today, and do what the law required," said Charles Hatfield, a lawyer for redistricting opponents.

The court ordered Hoskins to appear at another hearing Thursday afternoon to resolve the contempt motion against him.

Election officials were supposed to have ballots finalized on Tuesday so workers could begin preparing ballots to be mailed out before Sept. 19th.

Richard von Glahn, executive director of People Not Politicians, the group that organized the Democratic redistricting opposition, said the decision "settled" the fight over Missouri's maps.He blamed Hoskins for any administrative chaos.

"Missourians don't need a Secretary of State who manufactures confusion; they need one who follows the law," von Glahn said in a statement. "Denny Hoskins has had every chance to do that and chose not to."

Missouri's House delegation currently has six Republicans and two Democrats. The now-suspended new map would likely have shifted that to 7-1 by redrawing longtime Democratic Rep. Emanuel Cleaver's district to heavily favor Republicans.