Special American accent - southern pastors?

Once in a while I'll hear a sort of accent that I can best describe as what you'd imagine some Southern state pastor.

I've heard people like Jesse Dollamore to a sort of impression of this when he speaks about people claiming to speak to God.

When I hear that accent I picture those huge mass awakening tents that you see in movies and a very passionate pastors hyping up the crowd.

I just can't quite pinpoint that accent. Do anyone happen I know where that's from?