The definition of bait is to use any kind of lure or enticement, so it is my thought that if you use bait piles, food plots, scent lures, mineral licks, etc then you are baiting. As far as I know some of these are legal in all states so baiting is technically legal in all states........
If you only mean bait piles, I have hunted in areas where it was legal and areas that it was not legal. If you are trying to harvest a mature buck I don' t think a bait pile is going to up your odds. I personally don' t have any problem with scattering corn or other food sources for hunting.