According to the Arizona Republic, the suit was filed late Wednesday at a point when GOP candidate Martha McSally had a lead of about 17,00 votes against Democratic candidate Kyrsten Sinema.
Democrat Kyrsten Sinema and Republican Martha McSally tie at 46 percent apiece among Arizona likely voters.
There are still hundreds of thousands of votes to be counted in the last one percent of districts (including the very blue Tucson), with many speculating that the victor will not be named for several days.
Lawyers who filed the suit say they'd be happy if Mahoney chose to order the state's more rural counties to follow the same procedures, which would have the effect of expanding the vote count.
The Maricopa County Elections Department said in a statement there were approximately 472,000 ballots left to process and estimated about 195,000 of these are early ballots, provisional and out-of-precinct ballots that voters cast or dropped off on Election Day. Republicans said it was about following the law and having a timely ballot count.
In those cases where the signature on file does not match the signature on the ballot, the county recorder may call the voter to verify if the person did in-fact sign the envelope containing the ballot.
Some of the clearest examples of third party spoilers have been on the presidential level, with Ralph Nader being seen in that role by many in the 2000 election.
The verdict in the bruising contest to replace Jeff Flake has both parties on edge, almost 48 hours after polls closed, because of Arizona's slow tabulation procedures.
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.
A hearing is scheduled for Friday in Maricopa County Superior Court, Eric Spencer, elections director for the Secretary of State, told the Republic.
Both Sinema (88 percent) and McSally supporters (88 percent) have a high degree of vote certainty, and equal numbers of Democrats (50 percent) and Republicans (50 percent) are extremely interested in the election. The most populous part of Arizona, Maricopa County, said it won't start releasing late earlies and some other votes until late Thursday. "There are a lot of outstanding ballots - especially those mailed-in - and a lot of reasons to feel good!"
The historic race will see Arizona elect its first female senator.
Democrats hope Sinema can reverse a decade-long losing streak in all Arizona statewide races. The GOP notched victories in Attorney General, Treasurer and Secretary of State races as well.
The avid triathletes are battling over the seat vacated by Sen.
During her 2016 campaign to be re-elected to her Tucson area swing district House seat, McSally criticized Trump for attacking the parents of an Army captain killed in Iraq and for a videotape in which the future president bragged about sexually assaulting women. Jeff Flake, a Republican who decided not to run for re-election because he realized his criticism of President Donald Trump made it impossible for him to survive politically.