I have been reading about Frank Hamer lately, and an episode where the governor of Texas lost to a political machine that won with massive voter fraud occurred.
The governor was warned about the fraud and chose not to do anything about it until AFTER the election.
Just as now, the courts and the legislature did nothing about it. If you want to stop fraud, you apparently have to prevent it in the first place. It seems there will be no remedies after the fact.