A much-anticipated Supreme Court ruling involving challenged Virginia House of Delegates districts could cause upcoming primary elections to be postponed — leaving key electoral dates in doubt as Democrats seek to claim control of both legislative chambers.

Experts say a delay of the June 11 primaries may be needed if the court upholds the map drawn by the state legislature in 2011, which African American voters challenged as racial gerrymandering. Any change in maps could have a potentially seismic effect for the November elections. Republicans control the state House of Delegates 51-49 and the state Senate 21-19. With Democratic Gov. Ralph Northam having more than two-and-a-half years left in office, his party could potentially win full control of state government for the first time in more than a quarter-century.

“We’re at the point now where if the Supreme Court does reverse the lower court, one of two scenarios plays out,” said Michael McDonald, an associate professor at the University of Florida who focuses on elections. “One is that you have to move the primary dates and courts can do that, courts can change around dates of when elections are held. Another scenario is they say hold the election under the court-ordered districts so as not to upset the election, but next year, you have to have elections under the old maps.”

The justices in March heard oral arguments in the racial gerrymandering case, which involves 11 state House districts that have been in place for the last four election cycles. The maps, however, were contested on the grounds that the state legislature used race as the predominant factor when it drew the lines, which is a violation of the Constitution.

A panel of lower-court judges agreed in a ruling last year that the 11 districts were racially gerrymandered and called for new maps to be drawn.

That ruling, however, was appealed to the Supreme Court by state Republican leaders, who also asked the justices to put the mapmaking proceedings on hold while litigation continued. But the Supreme Court in January declined to intervene in the case, giving the go-ahead for a court-appointed mapmaker to continue with efforts to draw new voting boundaries.

Judges in the U.S. District Court for the Eastern District of Virginia approved the new map in February by a 2-1 vote.

A ruling from the Supreme Court is expected before the end of June, but experts contend the state could be cutting it close as they await word from the justices and prepare for the June primaries.

“If it means going back to the old map, the primaries might be delayed a little bit, but you have a map in place,” Michael Li, senior counsel at New York University’s Brennan Center for Justice, said.

The Virginia Department of Elections said it does not comment on pending litigation.

State House of Delegates Republicans' tenous hold on the chamber could be put at risk. The new map approved by the lower court moved roughly 370,000 voters to new districts, according to the Virginia Public Access Project. Of the 25 districts shifted under the new plan, six Republican-held districts would have Democrat majorities, including that currently held by House Speaker Kirk Cox, a Republican.

“There are six to eight Republicans that are really put in a tough spot under the court-imposed maps, so if those maps are kicked out, their reelection prospects would go up dramatically,” Quentin Kidd, a professor at Christopher Newport University in Newport News, Va., said.

Cox said after oral arguments in March that a ruling from the Supreme Court in favor of Virginia Republicans could mean the June primaries are delayed to ensure voters are reshifted back to their original districts.

The Supreme Court could in its ruling postpone the June primaries, particularly since candidates for the state legislature have already hit the campaign trail in districts drawn by the lower court. But Carl Tobias, a law professor at the University of Richmond, warned that a decision upholding the original lines drawn in 2011 could inject turmoil into the election.

“There must be a method to this madness in the Supreme Court, but I don’t know what it is,” he said. “It looks to be a mess, so maybe delay is what they will do. Maybe that’s the trump card they have in their back pocket.”

McDonald, meanwhile, predicted that as the June primaries draw near, the “odds are increasingly in favor” of the Supreme Court upholding the lower court’s ruling.

“As every day goes by without a decision by the Supreme Court, I would weigh more favorably the outcome is going to be that we’re going to see the new districts are going to be upheld,” he said. “Can’t say that with certainty, but it seems to me if they knew there was a majority that was going to overturn the lower court, they would’ve already issued a stay and action would’ve already been taken.”

The results of the November general election for the state legislature could have long-lasting implications, as state lawmakers elected then will be tasked with drawing new voting lines after the 2020 census.

Whether it’s the court-imposed maps that are upheld or the old maps will “dictate whether Democrats or Republicans control the House,” Kidd said.

"Republicans are in a far better position under the old map. Democrats are in a far better position under the court-imposed maps,” he added. “The layout of the pieces on the game board favor Democrats right now, but could go back in favor of Republicans.”