As The Rock himself mentioned- the original Sheriff Buford was a white man in his 40's so remember this is an adaptation of a 1970's movie script that was originally 'based' on a true story, so we are a pretty long ways out from accurately representing the original events- this is only representing the SPIRIT of the original true story. Soon, things come to a head and he has to make a choice as to whether he is going to put up with it, or Walk Tall. He quickly learns things in his hometown are not as he had left them and not for the better.
The Rock takes a page out of the Chuck Norris bible in his rendition of a special forces soldier returning to his home town.
