In his quest for a seat in the U.S. Senate, Rep. Mark Foley has rankled a group that is barely covered in most elections: nudists. Foley, of West Palm Beach, has hit the national TV and radio talk-show circuit in recent weeks to bash a Tampa-area summer camp not unlike most camps -- except that the boys and girls, ages 11-18, are naked. Foley, a Republican hoping to replace Sen. Bob Graham, says that letting naked teenagers play together is immoral and potentially dangerous. But ''naturists'' who say the camp exposes their children to a perfectly healthy and wholesome education...