Democratic candidate Kyrsten Sinema took the lead in the Arizona Senate race in new numbers released by the state Thursday night, flipping the race from what had appeared to be a GOP hold.
Republican Martha McSally led the vote after the polls closed Tuesday, but hundreds of thousands of ballots were still uncounted, officials said.
As the count comes in, Ms. Sinema has overcome a sizable gap.
The latest numbers give her 932,870 votes to Ms. McSally’s 923,260. Earlier in the day, the tally had stood at 856,848 for Ms. McSally and 839,775 for Ms. Sinema.
The McSally campaign said it still expects her to emerge victorious, pointing to its data modeling that showed the ballots counted Thursday, from Maricopa County, came in on early-voting days when GOP turnout was low.
The campaign said a large number of early-voting ballots dropped off on Election Day are still to be counted and they believe those will favor the Republican.
Republicans have so far netted two Senate seats — ousting three incumbent Democrats but losing one of their own.
The Arizona race would cut into that.
Meanwhile, another Republican leads, though the gap is tightening, as votes are being counted in Florida’s Senate race. That seat is currently held by a Democrat.
One more race, in Mississippi, is going to a run-off, where analysts predict the incumbent Republican will prevail.
Republicans could end up with anywhere from 51 to 54 seats when the dust settles.