Historian: There Used to Be Rampant Voter Fraud, But Not Anymore

After describing in detail some of the favorite tactics of political corruption, voter fraud and intimidation that was a pox on American democracy in the 1930s and 1940s, historian Thomas Fleming says this:

The president's party—which is still my party—has inspired countless Americans by looking out for the less fortunate. No doubt that instinct motivated Mr. Obama in his years as a community organizer in Chicago. Such caring can still be a force, but that force, and the Democratic Party, will be constantly soiled and corrupted if the right and the privilege to vote becomes an easily manipulated joke.

Becomes?  So, somewhere between the '40s and today our souls were purified and voter fraud ceased to soil our politics?  So the Daley machine in Chicago never happened?  Black Panthers don't patrol polling places?  ACORN hasn't been proven to have submitted tens of thousands of fraudulent voter registrations?  Good to know.  This would seem to be news.  How did we fix the system?  How did we take a vile and corrupt practice and banish it from our system?  This would seem to be news, no?