You would think we'd learn by now that when someone proposes a tax to control behavior, it's not about the behavior, it's about finding a justification to grab

You would think we'd learn by now that when someone proposes a tax to control behavior, it's not about the behavior, it's about finding a justification to grab money. For example, the soda tax. Why not treat them as controlled substances? All you need is a propaganda campaign a la Barry Bonds, et al.