The Republican National Committee and the Republican Party of Pennsylvania came to the Supreme Court on Monday, asking the justices to block a ruling by Pennsylvania’s highest court requiring election boards to count provisional ballots submitted by voters whose mail-in ballots had been deemed invalid.

The RNC and the Pennsylvania Republicans argue that the state supreme court had “dramatically change[d] the rules governing mail voting.” And in so doing, they contend, the state court had violated the U.S. Constitution by usurping the state legislature’s role in regulating federal elections.

The Republicans’ request came just eight days before election day, with Pennsylvania expected to play a key role in the 2024 presidential race.

In 2020, then-candidate Joe Biden won Pennsylvania by just over 80,000 votes, and polls have Vice President Kamala Harris and former President Donald Trump in a dead heat in the current race. The RNC and Pennsylvania Republicans posit that the dispute could affect “tens of thousands of votes,” and possibly even the outcome of the presidential election itself, but at least one voting rights expert has suggested that the number of ballots at stake in the dispute may be relatively low.

In Pennsylvania, voters using mail-in ballots are required to seal their ballot in an envelope – known as the secrecy envelope – and then place it in a second envelope, known as the declaration envelope, that they must sign and date. If a ballot-sorting machine determines that the ballot is “naked” – that is, that it lacks a secrecy envelope – then the voters are notified that they can cast a provisional vote at their polling place on Election Day.

Two voters whose provisional ballots were not counted during the state’s 2024 primary election went to state court, arguing that the election board was required to count their ballots. By a vote of 4-3, the Pennsylvania Supreme Court agreed that as long as the mail-in ballots are not counted, the provisional ballots should be.

Represented by John Gore, who served as the acting head of the civil rights division in the Department of Justice during the Trump administration, the RNC and the Pennsylvania Republican Party asked the justices to put the state court’s ruling on hold to give them time to file a petition for review.

Last year, in Moore v. Harper, the Supreme Court rejected a broad version of what is known as the “independent state legislature” theory, holding that although the Constitution gives state legislatures the power to regulate federal elections, state courts can still supervise the legislature’s exercise of that power.

In his opinion for the majority, Chief Justice John Roberts warned that the court’s ruling did not give state courts “free rein” to invalidate state election laws. Instead, he explained, because the Constitution gives state legislatures the power to make rules for federal elections, federal courts must “ensure that state court interpretations of that law do not evade federal law.” Specifically, he continued, state courts “may not transgress the ordinary bounds of judicial review such that they arrogate to themselves the power vested in state legislatures to regulate federal elections.”

But that is precisely what the Pennsylvania Supreme Court did in this case, the RNC and the Pennsylvania Republicans tell the justices. “When the legislature says that certain ballots can never be counted,” they say, “a state court cannot blue-pencil that clear command into always.”

The Pennsylvania Supreme Court was doubly wrong, they add, in “changing rules governing mail voting in federal elections after mail voting commenced and less than two weeks before Election Day.” Such a move, they allege, violates the Purcell principle — the idea that courts should not change election rules during the period just before an election.

Even if the court does not put the Pennsylvania Supreme Court’s decision on hold, they continue, the justices could follow the same path that they used in another election case from Pennsylvania in 2020, involving the counting of mail-in ballots that arrived after election day. In that case, Justice Samuel Alito – who initially fields emergency requests from Pennsylvania – ordered election boards to keep mail-in ballots received after election day separate and, if they are counted, to count them separately.

Alito instructed the challengers and the election board to file a response to the Republicans’ request by Wednesday at 4 p.m.

This post is also published on SCOTUSblog.