By Luc Cohen

(Reuters) – Pennsylvania election officials will be able to notify voters of any mistakes in their mail-in ballots and let them make changes, the state’s top court ruled, in a blow to Republicans who sought to block the practice in a state crucial to determining who will be the next U.S. president.

In declining on Saturday to hear a lawsuit brought by the Republican National Committee and its state affiliate against so-called notice and cure procedures, the Pennsylvania Supreme Court said the RNC filed the case too close to the Nov. 5 election, which pits Republican former President Donald Trump against Democrat Vice President Kamala Harris.

Pennsylvania is one of seven key battlegrounds likely to sway the state-by-state Electoral College outcome that determines the winner of U.S. presidential elections. Whichever candidate wins Pennsylvania will receive 19 electoral votes toward the total of 270 needed for victory.

The case is one of more than 120 voting-related lawsuits the RNC is involved with across 26 states. Republicans say they are trying to restore faith in elections by ensuring people don’t vote illegally, but some legal experts and voting rights groups argue the legal blitz is meant to lay the groundwork to challenge potential losses and suppress votes for Democrats.

The Republican push has yielded some victories.

In another ruling on Saturday, the Pennsylvania Supreme Court declined to hear a case brought by voting rights groups against a state requirement that mail-in ballots must bear the correct date in order to be counted. The court also said that case was brought too close to the upcoming election.

The use of mail-in ballots has surged since the COVID-19 pandemic. Trump, who falsely claims his loss to President Joe Biden in the 2020 election was marred by fraud, has criticized mail-in ballots as unreliable without evidence.

In asking the court on Sept. 18 to block county election boards from adapting “notice and cure” procedures, the RNC argued that the state’s legislature had not granted the local boards the authority to adopt them.

In a Sept. 20 court filing, the Democratic National Committee and its state affiliate argued that the state’s election laws indeed gave local boards the authority to implement such measures, and said the ruling the Republicans sought would prevent local officials from facilitating voter participation.

Charles Lutvak, a spokesperson for Harris’ campaign, in a statement called the Pennsylvania Supreme Court’s decision “a victory, not for Democrats but for our democracy.”

A spokesperson for the RNC did not immediately respond to a request for comment.

(Reporting by Luc Cohen in New York; Editing by Noeleen Walder and Bill Berkrot)