Behind-the-scenes battles: Legal challenges that could impact the vote before Election Day begins

From issues including mail-in ballots, drop boxes and concerns about ineligible voters, here are some of the high-profile swing state cases and where they currently stand.

Arizona

Arizona Secretary of State Adrian Fontes acknowledged in September that 218,000 people in the state were allowed to register to vote without proof of citizenship despite state law that requires it. A state court set a deadline of Monday for production of a full list of affected people so that the recorders of each county can verify the citizenship of voters who had not previously provided proof of citizenship.

The Maricopa County Recorder's Office said in a statement to Fox News Digital on Monday before receiving any list that approximately 2,000 people had tried to submit voter registration updates and subsequently received notices that they had to prove their citizenship. 

"These voters were contacted individually to let them know their registration was incomplete. However, after further consideration, the decision was made to fully restore those voters from the not-registered status, only if they were previously an existing, registered voter," the statement said. 

Georgia

Also in Cobb County, as well as in Fulton, Dekalb and Gwinnett Counties, the Republican National Committee sued, claiming that election offices improperly opened over the weekend to allow voters to drop off their mail-in ballots in person. The RNC cited state law that says drop boxes should be closed after the end of the early voting period, which was Friday. A state court said the county elections offices had the discretion to open for additional hours.

Another Georgia case involved Fulton County's offices being open over the weekend for dropping off mail-in ballots. At first, poll observers were barred from entering, with Fulton County elections director Nadine Williams stating that they were not allowed because it was a county office and not a polling site. Just hours later, it was announced that observers would be permitted after all.

Nevada

A lawsuit from the Trump campaign, RNC and Nevada Republican Party opposing the potential counting of mail-in ballots that the state receives after Election Day that do not bear a postmark. The state Supreme Court ruled that such ballots can still be counted up to three days after Election Day. There is a similar case in federal court where challengers also lost but are appealing to the Ninth Circuit Court of Appeals.

The same issue was also brought before the Fifth Circuit after a case was brought in Mississippi, and while the court said such ballots cannot be counted after Election Day, the ruling does not apply to this year's election.

North Carolina

The RNC also has a lawsuit in North Carolina, involving 225,000 people it alleges are improperly registered because they had used an old form that did not ask for their driver's license number or the last four digits of their Social Security number. The RNC claims that this violates the Help America Vote Act (HAVA).

"Because of these errors, the North Carolina voter rolls, which both HAVA and state law mandates that Defendants regularly maintain, are potentially replete with ineligible voters - including possible non-citizens - all of whom are now registered to vote," the RNC and North Carolina GOP said in a court filing.

Pennsylvania

Republicans scored a win when they appealed a court ruling that said mail-in ballots without a required handwritten date could still be counted. The Pennsylvania Supreme Court overruled, saying that handwritten dates must be on the ballots.

The GOP was not so fortunate in a separate case in which it sought an emergency appeal from the U.S. Supreme Court after the Pennsylvania Supreme Court ruled that provisional ballots should be counted if voters' mail-in ballots were disqualified for technical errors, such as not being in mandatory secrecy envelopes. Republicans cited a state law that they argued prohibited voters from casting provisional ballots if they had already submitted mail-in ballots on time.

The U.S. Supreme Court turned away the RNC's appeal, with Justices Samuel Alito and Clarence Thomas issuing a statement that made clear that because the case only involved two votes in a small county, it would not have impacted the results of the election either way.

Both parties won legal challenges when voters in multiple counties did not receive mail-in ballots on time. Democrats in Erie County sued when as many as 20,000 voters did not receive their ballots from a third-party vendor on time. A judge ruled that the Erie County Board of Elections had to remain open last Friday and Saturday so voters could fill out ballots.

In Bucks County, Republicans sued over voters waiting in line for mail-in ballots being turned away at 5 p.m., even though they had been there waiting. A judge swiftly ruled that voters should get an additional three days to apply for a mail-in ballot.

Another Pennsylvania case involves six Republican members of Congress who sued Pennsylvania's State Department with allegations that overseas voters' ballots were vulnerable to fraud because those voters were not made to adhere to the same identification requirement as absentee ballot voters in the U.S. The GOP lawmakers lost when a judge dismissed their case based on standing, timeliness, not presenting a viable cause of action and failing to join indispensable parties.

One situation that remains ongoing involves a potential voter fraud operation that is under investigation. Officials have said that several counties have seen large batches of voter registration forms and mail-in ballot applications that were suspicious. In Monroe County, District Attorney Mike Mancuso said that some of the forms detected in his county were submitted by "Field and Media Corps," an apparent subsidiary of Fieldcorp, an Arizona-based organization working in Lancaster County.

This was after officials in Lancaster County reported receiving 2,500 forms marked as suspicious for having false names, duplicative handwriting or unverifiable or incorrect identifying information.

The applications reportedly were not limited to a single party and were collected in various spots across the county.

One more case in Pennsylvania involves Elon Musk and his contest to award $1 million each day to an individual who registers to vote and signs a pledge to support the First and Second amendments. Philadelphia District Attorney Larry Krasner sued Musk and his PAC, claiming that the contest is an illegal lottery, and the Justice Department warned the Tesla CEO that there could be federal law issues because it is illegal to pay people to vote.

Musk has countered that he is not requiring anyone to vote in order to win the prize, only to register and sign the petition. He attempted to have the case moved to federal court but was unsuccessful. A hearing in the case was set for Monday.

Wisconsin

On Monday, the RNC announced that it is suing the Milwaukee Elections Commission over a city plan that was announced over the weekend, which says some precincts will limit poll watchers on Election Day to just one Democrat and one Republican, with outside organizations being barred.