The U.S. Supreme Court refused to stay a Pennsylvania Supreme Court ruling protecting absentee voting rights in the state on Monday by locking 4-4 and thus accepting the lower courts decision in the case.

While the non-decision is a victory for voting rights advocates, its also an ominous warning sign for a court soon to seat a new conservative justice: Conservatives on the court could return to this case soon, with a new majority, and potentially hand the 2020 election to Donald Trump .

For now, Pennsylvania absentee voters will be able to mail their ballots on or before Election Day and have them still count if they arrive up to three days after the election, as the state Supreme Court ruled. Many states allow ballots to arrive after Nov. 3 so that people voting by mail dont effectively have an earlier election deadline than people who go to the polls.

But four justices Clarence Thomas, Samuel Alito, Neil Gorsuch and Brett Kavanaugh voted to prevent the implementation of this new rule and to consider a radical argument that could eviscerate the right to vote granted in 49 state constitutions.

By taking away the power of state courts to interpret what their own state constitutions say about the right to vote, the soon-to-be six conservatives appointed by Republicans on the Supreme Court could become the ultimate arbiters of any expansion of voting rights.

The looming confirmation of Justice Amy Coney Barrett, who likens her judicial philosophy to the late arch-conservative Justice Antonin Scalia, could potentially provide the fifth vote to take up this issue at a later date or even intervene in Pennsylvania in the days before or after the election.

A newly seated Justice Barrett casting a fifth vote in this type of case would basically allow the U.S. Supreme Court to impose its restrictive view of the right to vote not only to the U.S. Constitution but also to state constitutions, said Josh Douglas, an election law expert at the University of Kentucky College of Law.

When the Supreme Court refused to stay the Pennsylvania Supreme Courts decision, it never took up the case or ruled on its merits. The case is technically still live, and the court could theoretically pick it back up prior to the election.

Another possibility is that a close race in Pennsylvania between President Donald Trump and Democratic Party nominee Joe Biden could lead to post-election litigation. Im counting on them to look at the ballots, definitely, Trump said on Sept. 30 about his desire to see Barrett confirmed to the Supreme Court before the election.

Trump could then make the same argument presented by Pennsylvanias Republican legislators that the state Supreme Courts ruling extending the ballot receipt deadline was unconstitutional and, therefore, invalid. This is one argument that could lead to the invalidation of all ballots postmarked by Election Day and received in the three days afterward.

This provides yet more fuel for a potential post-election nightmare scenario , in which there is no clear winner for weeks as Trump presses his case in the courts, and Republican legislators in key states like Pennsylvania seize on the uncertainty to send Trump electors to Congress.

At issue is the argument put forward by Pennsylvania Republican legislators that only a state legislature, and not a state court, may change state election law. The Pennsylvania Supreme Court extended the states absentee ballot receipt deadline by finding that voters casting their ballots through the mail due to the coronavirus pandemic could be hindered by delayed mail delivery in a manner that violated the state constitutions right to vote.

Pennsylvania Republicans argued that the court usurped the legislatures power to change the conduct of the election, since the U.S. Constitution vests the power to appoint state electors for the presidential election in such Manner as the Legislature thereof may direct.