A Florida judge on Saturday struck down congressional district lines for northern Florida advocated by Gov. Ron DeSantis, ruling that the Republican governor's map had improperly diluted Black voting power.

Circuit Judge J. Lee Marsh concluded that the congressional boundaries -- which essentially dismantled the seat once held by Al Lawson, a Black Democrat -- violated the state's constitution, which protects minority-access districts.

Marsh's order blocks the state from using the map in congressional elections and orders the legislature to draw a new one. The DeSantis administration is expected to quickly appeal the case all the way to the Florida Supreme Court.

The eventual outcome in Florida -- and other litigation pending in states such as Alabama and Georgia -- could play a significant role in which party controls the US House of Representatives after next year's congressional elections. Republicans currently hold a narrow majority in the chamber.

Voting and civil rights groups that brought the challenge hailed the decision Saturday as a rebuff to an aggressive effort by DeSantis -- who is seeking his party's presidential nomination -- to implement a map that heavily favored the GOP. In a rare move last year, DeSantis inserted himself into the redistricting process by vetoing a map drawn by the Republican-led legislature that had preserved existing districts represented by Black Democrats. Instead, he submitted his own map that lawmakers approved in a special session that DeSantis called.

"Voters should be empowered to pick their leaders, not the other way around," Jasmine Burney-Clark, the founding director of Equal Ground Education Fund, one of the groups that sued, said in a statement. "Today's ruling reinforces the fact that Gov. DeSantis forced a compliant Legislature to adopt a gerrymandered congressional map that diminished minority representation."

Aides to DeSantis and Florida Secretary of State Cord Byrd did not immediately respond to requests for comment Saturday.

Under the map used in last year's midterm elections, a significant number of Black voters from Lawson's district were moved into communities represented by White Republicans. Lawson ran for the redrawn 2nd District, a Republican-leaning seat anchored in Tallahassee, and lost to GOP Rep. Neal Dunn by 20 points.

Under a recent agreement, plaintiffs in the redistricting battle agreed to narrow the scope of the case to the North Florida district, dropping what had been a broader challenge to Florida's congressional map. The parties also agreed to pave the way for fast appeals to the state Supreme Court. Most of the judges on Florida's high court have been appointed by DeSantis, now in his second term.

A separate federal challenge to the state's congressional map is still pending.