Vote fraud charges in Texas come just a couple of weeks ahead of the midterm elections, and one of the nation's top election law experts says this case shines the light on one of the greatest concerns for election integrity - absentee ballot fraud.

Last week, four Texas women were charged with a total of 30 counts for carrying out a vote fraud operation during the Democratic presidential primary in 2016.  Prosecutors assert the women specifically targeted elderly residents, requested their ballots, voted for them, and mailed the ballots back in with fraudulent signatures.  The victims often had no idea they were targeted.

"This is typical of the way absentee ballots are stolen and fraudulently submitted.  There have been many cases very similar to this in other parts of the country," said Hans von Spakovsky, manager of the Election Law Reform Initiative at the Heritage Foundation.

Von Spakovsky also served on President Trump's Advisory Commission on Election Integrity.  He says this type of fraud was not something done on the spur of the moment.

"This was clearly an organized effort to steal the absentee ballots of individual voters, although we do know that it happens sometimes with family members, particularly parents who have been incapacitated by age or otherwise," said von Spakovsky, who says the voter fraud isn't even the most disturbing part of the Texas case to him.

"The key thing for people to notice here is that this wasn't detected by election officials.  They didn't know this fraud had occurred.  It was only a particular political consultant who was concerned about the election and who started looking closely at the absentee ballots to see if there was a problem," said von Spakovsky.

The Texas case is one of the bigger fraud prosecutions in recent years, but it's not alone.

"Some years ago, the Florida Department of Law Enforcement actually issued a report about numerous cases of absentee ballot fraud.  And they called absentee ballots the tool of choice of vote thieves," said von Spakovsky.

The problem goes beyond Florida too.

"Just a couple of years ago, several individuals were convicted in Troy, New York, who were engaging in similar activities, basically stealing the absentee ballots of voters.  They targeted a poor neighborhood and one of the campaign consultants who was found guilty was asked why they targeted this particular neighborhood.

"They said these were individuals who are probably least likely to complain or notice that their absentee ballot has been voted by someone else," said von Spakovsky.

Listen to the full podcast to hear why von Spakovsky believes there are thousands of these cases around the country, why he can't estimate the extent of such fraud, and what would help to stop it.