No I do not. I was not aware of the vast ghettoes. But some kind of middle class has to exist as the article headline talks about air conditioning - in Germany air conditioning is not common even in the upper middle class - this may be different in the US - idk.
Germany is way farther north though. Houston is further south than Israel, about the same latitude as Kuwait City and the Sahara Desert. The temperature averages 20-30°F warmer than Berlin (33-40°C), or put another way, Berlin's record high temperatures are a typical day in Houston. Also very humid since it's right near the ocean. Comparison charts:https://weatherspark.com/compare/y/9247~75981/Comparison-of-...
So yes, air conditioning is very common there, even if you're poor that's one thing you will try to find a way to get.
In the ghettos it's normally an old window unit, not central AC. Also shotgun shacks, which are houses setup with a straight-through floorplan so that if you open the front and back doors the whole thing becomes kind of a wind tunnel. Not as good as AC, but better than nothing.
In those neighborhoods, you'll also often see people (especially elderly and children) hanging out at the neighborhood church or mom and pop store, where there is air conditioning, if they don't have AC or it isn't working.
“Vast ghetto” is a bit extreme but a lot of the gulf coast is very poor indeed. Texas has plenty of very poor neighborhoods as does Louisiana, Mississippi and Florida right in prime hurricane paths.