On one hand you can see the point of that senator. Air rage can be fuelled by alcohol (and most certainly the effects of nicotine withdrawal, as you pointed out, can do this too). Many people say "If you can't go 12 hours without a cigarette you're a lost cause". Can the same be said for alcohol? You may not be addicted to it but you enjoy it, like smokers enjoy a cigarette.
On the other hand though, wheres the harm? When you drink you're not harming others with your breath, and if you are a responsible passenger you wont go overboard and become disruptive. If you appear to be drinking too much, the cabin crew can deny you any more drinks. Why punish the others who can handle it and dont cause trouble?
Kermie
