Casey campaign, refusing to concede, accuses McCormick of trying to 'disenfranchise' voters with lawsuits

Fox News Digital reached out to the McCormick campaign for comment, but they did not immediately respond.

As of Wednesday afternoon, McCormick was leading Casey by 29,338 votes, or a margin of 0.43%, according to the Pennsylvania election results website. If the margin remains below 0.5%, an automatic recount is triggered under Pennsylvania law. 

McCormick also asked that any provisional ballots from voters "who had requested mail-in or absentee ballots be sequestered and held pending action from the U.S. Supreme Court, or, in the alternative, that a global challenge be permitted as to all such ballots." In Genser v. Butler County, the state Supreme Court ruled last month that mail-in ballots that arrived on time but lacked dates or had the wrong dates on their envelopes could still be included in the vote count. 

McCormick was leading by more than 30,000 votes when the AP called the race at 4:09 p.m. Thursday. Though there were an estimated 91,000 votes still outstanding at that time, the AP asserted that there were not enough in areas supporting Casey for him to make up the difference. Senate Majority Leader Chuck Schumer, D-N.Y., initially declined to invite McCormick to the new-senator orientation this week, citing thousands of votes still yet to be counted. 

Fox News' Deirdre Heavey contributed to this report.