It goes without saying that my identification of southern accents is ignorant, I'm not from the south. I'm sure southerners can identify minute details in southern accents. I can do the same on my own turf e.g. I can recognize NYC accents, and I can recognize specifically if the accent is from Brooklyn, Queens, etc. And I can break it down even further into specific regions within the boroughs.
What I do know is that in the areas I've been to (mostly along the country side) people have very similar accents to what you see in southern-based movies and documentaries that involve subjects of racism and slavery circa 1800-1900. As a minority, it makes me extremely uncomfortable when I'm in a Denny's and there's 50 people around me that sound like Leonardo DiCaprio from Django. The staring doesn't help either, which is an odd experience for me because I'm really light-skinned for my ethnicity and my hair is usually long enough to hide my Hispanic features, but they can still tell.
So I start to add all of these things together: what I read in the media about the rampant racism in Texas, the accents that match what I see on southern-based Movies/Documentaries about injustice/hate, and my own personal experience with the weird looks I get. It just makes me not want to step foot in there ever again, and it makes articles like these seem par for course. If I feel that way and I'm practically white (look at my avatar) I cannot even imagine the horror African Americans would experience in such a place.