They probably went to the poorest county in the state to do their "sampling"
You can make MS look however you want if you pick the right county or town. I could make it look like a bunch of spoiled upper middle class white women if I went to Southhaven MS. Nothing but poor black people if I picked inner Jackson or Meridian. Nothing but liberals if I picked Biloxi.
And this isn't specific to southern states. I could probably make Cali look like a bunch of rednecks if I picked two specific southern California counties. (and before you get all in a rage over this comment, go browse peopleofwalmart.com for a bit and look at where the pictures are taken.)