On Thursday evening, the Arizona secretary of state's office published newly counted votes from these counties and others in the first significant update to the Senate contest since election night, when the race was too close to call.
According to Garrett Archer, an analyst for the secretary of state's office, Maricopa County still has approximately 345,000 ballots outstanding.
Angela Green, the little-known Green Party candidate who dropped out of the race days before the election, only to throw her support behind Sinema, has 43,838 votes.
As of Thursday morning, McSally was leading Sinema by a little more than 17,000 votes. She had 856,848 to Sinema's 839,775.
The verdict in the bruising contest to replace Jeff Flake has both parties on edge, nearly 48 hours after polls closed, because of Arizona's slow tabulation procedures.
Injecting more drama into the vote-counting process, Wednesday Republican county party officials filed suit in Maricopa County Superior Court to block election officials in several Arizona counties from counting early ballots received by mail after polls close, if those ballots require signature verification.
If the signature on a ballot dropped off on Election Day does not match the signature on file for a voter, recorders in several Democrat-heavy counties – including Maricopa County and Pima County – call voters to verify that they signed the ballot for up to five days after the election.
Maricopa County Recorder Adrian Fontes, a Democrat, swiped back on Twitter, telling the GOP officials, "Bring it."
In the complaint, lawyers for the Republicans claimed that the lawsuit was meant to ensure counties are following a uniform tabulation process on early ballots. "Arizona has an early voting regime that is far more permissive than those enacted in other states," the complaint says.
A Superior Court judge said on Thursday that counties can keep tabulating these ballots, the Arizona Capitol Times reported, but another hearing is scheduled for tomorrow.
In a statement anticipating the new results this afternoon, Sinema's campaign manager, Andrew Piatt, said, “Arizonans must have faith that their votes are counted, and we are working diligently to ensure that count proceeds in a fair, transparent, and timely manner that voters can trust."
Denied.— Adrian Fontes (@Adrian_Fontes) November 8, 2018
Thank you Judge.
I’m gonna keep counting ballots now.#ProtectDemocracy
An estimated half a million votes still need to be tallied after these new results come in, he said. "Once they are counted, we are confident that Kyrsten Sinema will be the next Senator for the state of Arizona," Piatt said.
The race was too close to call on Tuesday night, so McSally and Sinema were absent from the watch parties where other candidates declared victory or conceded. (McSally did, however, post a photo of her seated in the dentist's chair on Twitter on Thursday.)