MATHIS, Texas --- South Texas is rife with agents from local political camps who prosper by organizing mail-in ballot fraud, elections administrators and other observers in the region say, even after a state-level push to curb the wrongdoing. The office of state Attorney General Greg Abbott has several open investigations into the practice of shepherding mail-in ballots, mostly in the name of elderly voters. But perpetrators leave a sparse paper trail, election officials say, and the potential five-figure earnings for local operatives far outweigh any punishment levied for committing fraud, typically a misdemeanor. “It’s a racket,” said Nicole Perez, general...