Republicans in the Pennsylvania Senate on Monday asked the US Supreme Court to block a ruling from the state’s Supreme Court allowing mail-in ballots received three days after November 3 to be counted if they are postmarked on that day.

The Pennsylvania Democratic Party filed a lawsuit in June challenging several aspects of the state’s election laws, including Act 77 of 2019 and Election Code, 25 P.S. §§2600-3591, arguing the rights of absentee and mail-in voters were at stake. The lawsuit contested the current state laws requiring all mail and absentee ballots to be delivered to the county elections office by 8:00 PM on Election Day, alleging such deadlines would be unconstitutional during the COVID-19 pandemic and because of problems documented with the postal service.

On September 17 the Pennsylvania Supreme Court ruled that Pennsylvania’s election laws allow counties to set up drop boxes and satellite offices to accept mail and absentee ballot. Additionally, the court ruled that valid mailed ballots postmarked by 8:00 PM on Election Day must be counted if received by 5:00 PM on November 6, and ballots with missing or illegible postmarks are to be treated as having been timely mailed if received by November 6, “unless a preponderance of the evidence demonstrates that [they were] mailed after Election Day.” The ruling was considered a major victory for Democrats.

However, in response to the ruling, Pennsylvania Senate Republicans filed an Emergency Application for Stay Pending Writ of Certiorari with the US Supreme Court. In their petition, Pennsylvania Senate Republicans argued that the state supreme court’s ruling was a violation of federal law that mandates holding elections on a single day. They further contend that the court’s decision is also a violation of the US Constitution’s Elections Clause because it was rendered by the judiciary, rather than the state legislature.