Dunno where you're getting that, but Austin is not "over 50% Hispanic" by any stretch of the imagination, it's only about a third. The non-Hispanic white population in the city proper is 48%, which is really damn high for an actual city-limits population of a large American city, let alone in the South/Southwest.
Houston and San Antonio, respectively, are at 24-25%. Here's the
latest census estimates on Austin/Travis County, Houston/Harris County, and San Antonio/Bexar County.
Now, census stats are imperfect for comparing these things, because different cities and states draw their lines much differently. "Pittsburgh" for example, only includes a really confined area, so outlying towns that are just a few miles from downtown and culturally indistinguishable from the city, like Wilkinsburg, are cut out of Census counts for the city proper. Meanwhile, "Nashville" and many other southern cities stretch on FOREVER and have reaches that would definitely be considered separate suburbs were the cities up North.
So everything is an approximation, of course, which is why you can also look at counties for certain cities to get a better sense. It's an unfortunate fact for NHL viability, and the game will grow slowly in cultural appeal as more cultures are represented, but demographics play a huge part in team viability.
The theory used to be HUGE CITY/BIG SUBURBS=BEST MARKET, but I think teams in the Atlanta, Phoenix, and Miami areas have shown that it's more about developing a strong team in an area that'll more readily adapt it into its culture. Income, size, demographics, relevant industries, you name it: Austin is a lot more like Nashville, perhaps the league's finest Southern success, than it is Houston or San Antonio, which more closely resemble the league's largest expansion/relocation failures.
