Have you folks who live outside of Louisiana ever heard of this word? I'm beginning to think this word might be unique to this area because I haven't heard it used outside of the south.
"Coonass" sounds kind of offensive if you don't know what it means, but it's almost looked at as a badge of pride. It's sort of used by the same class of folks who'd probably just be considered or consider themselves "rednecks" if they lived in other places, but there's a definite difference between the two.
Both terms are used here. "Rednecks" is sometimes used pejoratively to describe poor white people, in general. However, "coonasses" refers to those whites of a particular background, namely, Cajuns. It really isn't an insult. It's more like a signifier that people use to identify themselves as members of this group that has historically been looked down on and discriminated against, even by other poor whites.