The Pennsylvania Supreme Court, in a rare unanimous decision, stated that mail-in ballots cannot be thrown out because the signature on the ballot did not match the signature on voter registration records, the Associated Press reports.

“County boards of elections are prohibited from rejecting absentee or mail-in ballots based on signature comparison conducted by county election officials or employees, or as the result of third-party challenges based on signature analysis and comparisons,” the justices wrote.

The ruling is another victory for Democrats who seek to increase voter participation during the pandemic, encouraging states to accept more mail-in ballots to protect voters from the coronavirus.  The Trump campaign and republicans have been fighting such efforts.

The Secretary for the State of Pennsylvania, Kathy Boockvar, said in her court filings that arbitrary rejection of ballots based on signatures create “a grave risk of disenfranchisement on an arbitrary and wholly subjective basis.”

Such a rejection of a ballot is an irreparable harm, Boockvar noted, because the state does not have a requirement to notify the voter that the ballot had been rejected, nor does it have a way for a voter to submit a new ballot or verify the signature if the ballot is rejected.

Pennsylvania does not allow the processing or counting of mail-in ballots until 7 a.m. on Election Day, meaning that any challenged ballots would not be counted in the final total of votes.