The Pennsylvania Supreme Court extended the receipt deadline for mailed absentee ballots in that state to three days after Election Day in a ruling issued Thursday . Mailed ballots that are postmarked by 8 p.m. on Nov. 3 will count so long as they arrive by 5 p.m. on Nov. 6.

The decision is a victory for the states Democratic Party , which brought a challenge to state election laws that it said place burdens on voters trying to cast ballots safely during the coronavirus pandemic. It is a loss for President Donald Trump , who has claimed that he will lose the election only if there is fraud, which he falsely says will be rampant thanks to mail-in voting. Trump and Republicans in the state legislature intervened to oppose the extension of the ballot receipt deadline.

It is also a major ruling in the context of the 2020 presidential election, as Pennsylvania is viewed as one of the key swing states in the Electoral College. The extension of its ballot receipt deadline is among the most pivotal changes sought as part of a record-breaking number of election-related legal challenges across the country.

The decision likely means that tens of thousands of votes that would have otherwise been judged void will now be counted. When courts extended the ballot receipt deadline in Wisconsin ahead of its April 7 primary election, tens of thousands of ballots were counted that otherwise would have been discarded for arriving too late. Trump won Pennsylvania by just 44,000 votes in 2016.

Previously, ballots cast by mail in Pennsylvania had to arrive by 8 p.m. on Election Day to be counted. Any ballots arriving after that time became invalid.

Democrats argued that this cutoff was unreasonable due to the pandemic and the mail delivery slowdowns caused by both the virus and the efficiency reforms instituted by Postmaster General Louis DeJoy.

A majority of the state Supreme Court agreed that the pandemic equates to a natural disaster and that voters should not be impeded from casting ballots based on the obstacles that nature imposes. The court stated that the anticipated flood of mailed ballots and the U.S. Postal Services admission in an August letter to 46 states that it may not be able to deliver those ballots on time justified extending the ballot receipt deadline.

[W]e conclude that the timeline built into the Election Code cannot be met by the USPSs current delivery standards, the majority opinion says.