It’s not often that I recommend a book written by a politician because they usually aren’t, they’re ghosted. But former Sen. Fred Thompson’s “Teaching the pig to dance,” which hits the bookstores Tuesday, actually comes from his pen. It’s about his early life growing up rural in Tennessee, and it’s hilarious in the dry, self-deprecating way that is peculiarly Southern and instantly recognizable to anybody who grew up below the Mason-Dixon line.  The chapter “Rebel without a clue” is priceless, as is the discussion in the next chapter of the football coach surreptitiously called Stumpy.