A tied Supreme Court has allowed Pennsylvania to count mail-in ballots received up to 3 days after Election Day

• The Supreme Court has allowed Pennsylvania to count mail-in ballots received up to three days after Election Day.
• It lacked a majority to rule on a GOP attempt to block the measure, defaulting the decision back to the state Supreme Court.
• The state allows ballots to be counted if they are mailed on or before Election Day, even if their postmarks are illegible or missing.
• The split ruling illustrates the significant role Amy Coney Barrett would have in election disputes, as she's expected to be confirmed to the Supreme Court next week.

The Supreme Court has allowed Pennsylvania to count ballots received up to three days after Election Day, in a tied decision that did not approve a request from the state Republican party to stop the count.

The state's Supreme Court had extended the ballot receipt deadline as a measure adapting to the coronavirus pandemic and postal delays, but Republican officials requested the measure be blocked. The ruling requires county election officials to count ballots that arrive by November 6, as long as there's no evidence they were mailed after the polls closed on November 3, even if their postmarks were illegible or missing.

With a tied vote of four votes to four, the Supreme Court lacked a majority to issue a ruling. The split means that the decision defaulted to the decision from the Pennsylvania state Supreme Court, which permitted the deadline extension.

Pennsylvania is one of three crucial swing states — including Michigan and Wisconsin — won by Donald Trump in 2016 that appear to have record levels of mail-in voting this year, as Business Insider's Grace Panetta reported. Trump won the state by less than one percentage point.

The ruling is a victory for Pennsylvania Democrats, who have requested more than a million more absentee ballots than registered Republicans, The New York Times reported, citing the Pennsylvania secretary of state's office.

In their emergency application for a stay on the state court ruling, Pennsylvania conservatives argued that the three-day extension would be an "open invitation to voters to cast their ballots after Election Day, thereby injecting chaos and the potential for gamesmanship into what was an orderly and secure schedule of clear, bright-line 2 deadlines."

With Pennsylvania a key swing state, they added that "the new rules imposed by the decision of the Supreme Court of Pennsylvania (a body elected in partisan elections) could destroy the American public's confidence in the electoral system as a whole."

SCOTUS has historically been hesitant to overrule state decisions on electoral practices.

The Pennsylvania attorney general, Josh Shapiro, a Democrat, defended the state court's decision with a reference to a clause in the commonwealth constitution that says that "all aspects of the electoral process in Pennsylvania be open and unrestricted so as not to disenfranchise Pennsylvania voters," The Washington Post reported.

The SCOTUS vote was tied, with four conservatives — Justices Brett Kavanaugh, Clarence Thomas, Samuel Alito, and Neil Gorsuch — voting to block the measure. But the ruling also demonstrates the heavyweight role conservative judge Amy Coney Barrett will have when her nomination to the court is confirmed, as is expected next week.

In her confirmation hearings, Coney Barrett has refused to weigh in on key issues relating to elections, as Business Insider's Sonam Sheth has reported.

These include whether the president is able to delay or postpone an election — an idea that Trump floated over the summer — and said she would not recuse herself from any case surrounding a contested election.

The SCOTUS justices did not give a reason for their decision.