I'm all for non-smoking public places, and that includes bars and restaurants, which allow smoking sections where I live.  I draw the line at a law for bars & restaurants to be smoke-free, however.  I'd like to see local governments give benefits to bars & restaurants that choose to be smoke-free.
I personally would frequent a non-smoking restaurant (as long as the food isn't godawful) just for the clean air.  
As for the second-hand smoke effects, I am convinced that it is harmful to non-smokers and that is based on personal experience.
I once worked in an office that allowed smoking at our desks.  In that office was mysef and a smoking coworker.  This woman has a cigarette burning all day- she didn't smoke much but cigarette after cigarette would be propped in her ashtray filling the office with smoke.  I showered every day after work - I smelled like I worked in a bar.  I bought a smoke-eater candle to no avail.  I put up with it because I was a kid working in my first "real" job and she was so sweet I didn't have the heart to ask her to stop doing the thing that got her thru the day (as she put it) on my account.  That changed when I started getting sinus infections and had a hard time breathing in the office and had these intense stomach pains throughout the day.  Visits to my doctor ruled out any disease (thank god) and an ear, nose & throat specialist finally concluded that I'd developed an allergy to cigarette smoke (and the chemicals therein).  I left the job, worked in a smoke-free office for 6 months afterward and felt much better.  The only problem is that now, 10 years later, I still have allergies and sinus problems, culminating in sinus surgery a few years back.  
I know for a fact that being in that smoky office led to my sinus problems - I was there and I felt it happening to me.  And when I left they decreased which I don't think is a coincidence.
Smoke if you want to, that is absolutely your right.  I'd just as soon not be around it.  But I do think some laws are going a bit too far.  There are places I don't dine because of the smokiness and that's my choice.  I certainly wouldn't insist they change what works for them because of me; I just take my money elsewhere.  But public places (schools, offices, etc) should be smoke-free.  
That's just my humble opinion 

  (Well, I'm a Leo, so how humble can humble be really?  

 )