There isn't a significant minority population
It's actually majority-minority, and traditionally heavily polarized between Beaumont + Port Arthur (both plurality-Black) and everything else, as is typical for the Deep South. It's become less Black (raw population decreasing) and more Hispanic (raw population increasing) over the decades, thus creating a natural GOP swing that's been compounded by the substantial Hispanic swing right since 2012.
Unusually, it swung heavily Republican from 88 to 92, probably because of the 80s oil crash and subsequent rebound.