good screenplay/stellar direction/ and........
I believe that this film has a mythos and cult following embracing it for several reasons. But the first and foremost, in my opinion, is the opening frame.
How many other filmns with mega stars can claim to have the mega star, in his first appearance in the film, exit from a washroom in a rural gas station?
haven't seen anything like it since, probably never will.
and it's also an extremely Liberal film, a film that belittles the futile organization of local law enforcement over organized crime, and a film that illustrates the so-called respect that organized crime figures garner.
Good versus Evil with plenty of shadows.