It is not a class distinction in terms of socioeconomic standing.
There are very rich rednecks, especially here in Texas. They look down on "white trash" who may also be rednecks, themselves.
Many people in Texas refer to others as rednecks based on seemingly simplistic viewpoints and their approach on how to handling challenges, no matter how bizarre. Rednecks may not necessarily behave that way, but it's the response they put forward that earns them the name "redneck".
That's why I stressed roberstar's dependence on the dictionary to describe something he's had no first hand experience with is pure comedy.
You can't pick and choose one definition to fit a word that has myriad meanings in more than one context.
It's the same way "gay" went from meaning "happy" to "homosexual" to, for a time, "loser".