1984 New York Grand Jury Report on Voter Fraud Now Available | Election Law Blog
This is the essence of the GOP argument. Voter fraud happened in Brooklyn once upon a time, 40 years ago. A corrupt Democratic machine with election officials on the take conspired to stack the election. The problem was solved. Regulations and rules put in effect since pretty much ensure that this can't happen again. It doesn't stop the GOP whose crusade to stop "voter fraud" is in itself a fraud. Conspiring to keep possible Democratic Party supporters away from the polls is the actual purpose and lying about voter fraud is the means.
More work to do.