It’s deliberate. Republicans know that poor people are less likely to vote and when they do more likely to vote for Democrats who might actually help them.

As for low voter turnout, Republicans have closed over 700 precincts in minority areas over the past few years. The availability of early voting should address that issue since you can vote at many places outside a precinct during that period, but still too few voters get to the polls. Some of that may be minority voters who lack transportation, and Texas has virtually no public transportation, and voting locations accessible only by car. The voting rate for Hispanics tends to be lower than that for whites, possibly indicating that Hispanics do not get time off from work to vote or fear intimidation from officials. Again, early voting is an option, but one not all possible voters use. Plus, years ago, many Hispanics were born at home and do not have the birth certificates needed to get registered to vote. The Democratic Party of Texas has improved in the past few years, but its efforts have been lacking since the days of Ann Richards.