Redneck used to mean some one who:
Worked in the sun for a living and thus had a burned and red neck; from the country laboring class.
These were typically people from the "country" areas who didn't use or could not afford sun protection gear/products and who were looked down upon by the city folk (from my experience.)
Redneck does not inherently mean Bigot or Racist, despite it being a slang term to begin with which is now also being used to describe bigots. Redneck has two definitions; hick or bigot, in my opinion. If they were all Bigots then I doubt Comedy Central would name a comedy tour "The Redneck Comedy Tour."
Redneck Defined.
(hick has allready been defined.)