A curious thing about gambling in America is that it is extremely popular, yet has a bad reputation--and I don't mean the unsavory way in which gambling licenses are awarded . I am talking about the moral realm, as witnessed in the clucking over William Bennett's expensive habit. Casinoland's high rollers are perceived as inhabiting a zone somewhere between immoral and diseased, and have great difficulty defending themselves. Yet in their own lives most Americans demand ever more gambling opportunities.…