HARRISBURG, Pa. (AP) — Pennsylvania election officials said Wednesday that the number of mail-in ballots rejected for technicalities, like a missing date, saw a significant drop in last month’s primary election after state officials tried anew to help voters avoid mistakes that might get their ballots thrown out.

The success of the mail-in vote could be critical to determining the outcome of November’s presidential election in Pennsylvania when the state is again expected to play a decisive role in the contest between Democratic President Joe Biden and former President Donald Trump, a Republican.

Pennsylvania’s top election official, Secretary of State Al Schmidt, said counties reported a 13.5% decrease in mail-in ballots that were rejected for reasons the state had tried to address with a redesigned ballot envelope and instructions for voting by mail. That drop was calculated in comparison to the 2023 primary election.