Current Houston resident here: Nope.
Houston is full of immigrants–from places like New York City, Los Angeles, Mexico City, Lagos, Saigon, Bombay, etc. The very oldest Houston money came from cotton–but Big Oil made the city what it is. Slavery was illegal under Mexican rule, so the dreadful institution only took root on Texas soil in the years between Texas Independence (1836) & Juneteenth–1865.
There are some Old Confederates in Texas, but they are outnumbered*. Especially in the cities. (In San Antonio, even more so–since neither the Mexicans nor most of the Germans held with slavery.)
- Even the serious nutcases fantasize about seceding to make an Independent Texas, not to join a reborn Confederacy. Texas chauvinism prevented the Lone Star flag from ever being besmirched with Confederate imagery.