Your link refers to “one count of an election law violation,” which is different from voter fraud. A few people in all of ACORN’s many branches were hired to register voters and got caught submitting voter registrations with fake names. They were being paid per registration, so it’s not hard to see why they were tempted. As Factcheck.org explained, “The $8-an-hour employees were charged with providing false information on voter registration forms, and in one case with making a false statement to a public official. Five of the seven…pleaded guilty. ACORN was fined for exercising insufficient oversight, but it was not charged with masterminding any kind of deliberate fraud.”
Since fake voters aren’t going to show up at the polls, the kind of voter fraud the right-wing called “massive voter fraud” wasn’t even possible, but it keeps pushing the false narrative any way.