The Supreme Court voted 5-3 on Wednesday to deny a bid from Pennsylvania Republicans to expedite their request to shorten the deadline for receiving mail-in ballots. Newly confirmed Justice Amy Coney Barrett did not participate in the decision.Why it matters: A lower court ruling allowing ballots to be counted until 5pm on Nov. 6, as long as they are postmarked by Election Day, will remain in place for now.Between the lines: Conservative Justices Alito, Thomas and Gorsuch wrote in a separate opinion that it's too close to the election to take up the case, but it could still be reviewed after the election if late-arriving ballots make a difference.Earlier on Wednesday, Pennsylvania's state government directed election officials to separate ballots received before and after 8pm on Election Day in case the Supreme Court decides the late-arriving ballots must be thrown out.While Alito leaving the door open for a fast post-election decision will spark some concern among Democrats, only two of the eight judges who considered the case concurred with him.The court last week was deadlocked 4-4 on a previous request from Pennsylvania Republicans to shorten the deadline to Election Day. The GOP likely filed another motion because the court now has a ninth justice, according to elections expert Rick Hasen.Worth noting: "Justice Barrett did not participate in the consideration of this motion because of the need for a prompt resolution of it and because she has not had time to fully review the parties’ filings," according to a statement from the Supreme Court's Public Information Office.The bottom line: There's a real chance that Pennsylvania — and thousands of ballots that don't arrive until after Election Day — could decide who wins the presidential election.Read the statement from Alito, Thomas and Gorsuch.