Rudy Baylor, the hero of "The Rainmaker,'' works the other end of the scale from the legal superpowers in most of John Grisham's stories. He's a poor kid who has scraped through law school by the skin of his teeth, is living in his car as the film begins and signs on with a firm where most of the work is done by a paralegal, and the boss wears the kinds of cuff links you can get rid of in a hurry at a pawn shop.