As per the mention about alcohol, I'll bite... First, I drink very rarely and never to the point of getting wasted. I think those who drink and drive should be locked away for a very long time for reckless endangerment.
However, someone sipping alcohol in a restuarant is completley different than smoking. Why? The very simple reason that the alcohol doesn't seep through the air and get into my system whether I want it to or not. Smoke does.
I come from a family where everybody but me smokes. I've never smoked a day in my life. I've been asked if I smoke however, because I have a persistent "smoker's cough". I'm no medical expert, so I can't tell if it's actually related, but I'm sure growing up in a smoke-laden household did not help the situation. Also, my eyes are very sensitive to smoke and burn to the point where I cannot even keep them open when there is much smoke in the air. For this reason I can't ride in a closed vehicle with a smoker, nor can I enjoy myself at many clubs or types of places where smoke gets heavy.
When someone drinks alcohol, as long as they are responsible in doing so, I can be 1 foot away from them and it does not affect me in the least. When they light up - that is no longer the case - it affects me very much.