By Tom Hals and Jan Wolfe
(Reuters) - U.S. President Donald Trump's campaign said on Saturday it had filed a lawsuit in Arizona, its latest legal challenge over the results of the presidential election.
The campaign suffered losses in Michigan and Georgia courts this week, but Trump pledged on Saturday to go forward with a legal strategy that he hopes will overturn state results that gave Democrat Joe Biden the win in Tuesday's vote.
Legal experts said the cases the Trump campaign is bringing are narrow in scope and unlikely to change the outcome.
Below is a list of the cases that will play out in the coming days and possibly weeks. Trump's campaign said on Saturday more litigation would be filed in the coming days.
Several court battles are pending in the battleground state of Pennsylvania.
The Trump campaign is fighting Philadelphia election officials over vote counting in the city, which continued on Saturday. A state court on Thursday granted the campaign closer access to the proceedings, a ruling that officials have appealed.
The City of Philadelphia Board of Elections has said its observation rules were needed for security reasons and to maintain social distancing protocols.
Trump's campaign on Wednesday filed a motion to intervene in a case pending before the U.S. Supreme Court challenging a decision from the state's highest court that allowed election officials to count mail-in ballots postmarked by Tuesday's Election Day that were delivered through Friday.
U.S. Supreme Court Justice Samuel Alito on Friday night ordered county election boards in the state to separate mail-in ballots received after 8 p.m. EST on Election Day.
Pennsylvania election officials have said those ballots were already being separated.
The justices previously ruled there was not enough time to decide the merits of the case before Election Day but indicated they might revisit it afterwards.
Alito, joined by fellow conservative Justices Clarence Thomas and Neil Gorsuch, said in a written opinion that there was a "strong likelihood" the Pennsylvania court's decision violated the U.S. Constitution.
Pennsylvania's Secretary of the Commonwealth Kathy Boockvar has said late-arriving ballots are a tiny proportion of the overall vote in the state.
Trump's campaign said on Saturday it had sued in Arizona, alleging that the state's most populous county incorrectly rejected votes cast on Election Day by some voters.
The lawsuit, filed in state Superior Court in Maricopa County, said poll workers told some voters to press a button after a machine had detected an "overvote."
The campaign said that decision disregarded voters' choices in those races, and the lawsuit suggested those votes could prove "determinative" in the outcome of the presidential race.
A voter, a member of the media and two candidate campaigns sued Nevada's secretary of state and other officials to prevent the use of a signature-verification system in populous Clark County and to provide public access to vote counting.
A federal judge rejected the request on Friday, saying there was no evidence the county was doing anything unlawful.
GEORGIA BALLOT FIGHT
The Trump campaign on Wednesday filed a lawsuit in state court in Chatham County that alleged late-arriving ballots were improperly mingled with valid ballots, and asked a judge to order late-arriving ballots be separated and not be counted.
The case was dismissed on Thursday.
MICHIGAN BALLOT-COUNTING SUIT
Trump's campaign on Wednesday filed a lawsuit in Michigan to halt the vote count in the state. The lawsuit alleged that campaign poll watchers were denied "meaningful access" to counting of ballots, plus access to surveillance video footage of ballot drop boxes.
On Thursday, Michigan Court of Claims Judge Cynthia Stephens dismissed the case, saying there was no legal basis or evidence to halt the vote and grant requests.
U.S. POSTAL SERVICE LITIGATION
The U.S. Postal Service said about 1,700 ballots had been identified in Pennsylvania at processing facilities during two sweeps on Thursday and were being delivered to election officials, according to a court filing early Friday.
The Postal Service said 1,076 ballots, had been found at its Philadelphia Processing and Distribution Center. About 300 were found at the Pittsburgh processing center, 266 at a Lehigh Valley facility and others at other Pennsylvania processing centers.
U.S. District Judge Emmet Sullivan in Washington is overseeing a lawsuit by Vote Forward, the NAACP, and Latino community advocates.
Sullivan on Thursday ordered twice-daily sweeps at Postal Service facilities serving states with extended ballot receipt deadlines. The judge plans to hold a status conference on Monday.
(Reporting by Tom Hals in Wilmington, Delaware; Editing by Noeleen Walder, Jonathan Oatis and Paul Simao)