Voters drop off their mail in ballots in Philadelphia, Pennsylvania, November 2, 2020.Rachel Wisniewski | ReutersThe Postal Service on Election Day failed to deliver a significant percentage of mail-in ballots to several states that could determine who wins the presidential contest between President Donald Trump and Joe Biden, a court filing revealed Wednesday.The delivery rate is certain to be a key issue at a federal court hearing in Washington scheduled for noon ET Wednesday in a case where a judge has ordered the Postal Service to sweep its facilities for remaining mail-in ballots.The states seeing relatively poor levels of mail deliveries of ballots include Georgia, Pennsylvania, Michigan, North Carolina and Wisconsin, all of which have yet to declare victors in their tallies for Trump and Biden.The current vote tallies in those states show thin margins between the two candidates. The outcomes in those states could hinge on the mailed-in ballots.The data also showed that in South Florida, just 85.12% of the mail-in ballots were delivered on Election Day.Democratic hopes of winning Florida were dashed Tuesday in no small part due to Biden’s failure to rack up a large margin of victory over Trump in the Miami-Dade area, a region of South Florida that traditionally skews Democratic.Biden is expected to outperform Trump in mail-in balloting in multiple locations. Trump has cast doubt on the legitimacy of outstanding mail-in and absentee ballots where Biden’s results threaten his path to an Electoral College victory.In central Pennsylvania, just 61.3% of the mail-ballots in the postal system were delivered on time, the court filing shows. In Philadelphia, slightly more than 66% of the mail-in ballots had been delivered on Election Day.In Atlanta 82.2% percent of the mail-in ballots were delivered on Election Day, the court filing shows.Detroit postal facilities reported less than 79% percent of mail-in ballots delivered that day.In Greensboro, North Carolina, 72.9% percent of the mail-in ballots were delivered on Tuesday.And in Lakeland, Wisconsin, slightly less than 77% of such ballots were delivered, the filing revealed.Correction: The hearing is scheduled for Wednesday. A summary in an earlier version had the wrong day. Correction: The hearing is scheduled for Wednesday. A summary in an earlier version had the wrong day. This is breaking news. Check back for updates.