4,098 of the total 5,445 primary ballots were early voters and 2,800 of those were by mail!
To be eligible to vote early by mail in Texas, you must:
be 65 years or older;
be disabled;
be out of the county on election day and during the period for early voting by personal appearance; or
be confined in jail, but otherwise eligible.
Wouldn't be surprised if the same people who voted for LBJ then are voting 'absentee' now...and still in alphabetical order, of course.
You left out two of the most important ones:
Being dead and being a Democrat!
4,098 of the total 5,445 primary ballots were early voters and 2,800 of those were by mail!
The article states 55% of the registered voters...