The Denver Post says that cities like Pueblo (!) and Greeley (!) that have enacted smoking bans for restaurants and bars have not suffered the predicted drop in tax revenue that would signal that the ban was hurting those establishments. Instead, those receipts have risen at about the same rate as have receipts in cities like Denver that do not yet have the ban.
I'm not just a non-smoker, I'm allergic to tobacco. So you might think I would be a militant supporter of these bans. I'm really more of a mild supporter. I favor the bans primarily as a public health issue for the employees of bars and restaurants, who shouldn't have to face constant exposure to carcinogens any more than factory workers should. So I wouldn't have a problem with letting smokers have some separately ventilated area if the employees' exposure to the smoke could be reduced.
And I believe the fear of lost business displayed by many restaurant and bar owners is a classic example of market failure, where due to a herd mentality among the owners, smokers end up getting catered to all out of proportion to their representation in society. Less than 20% of adult Coloradans smoke, but without these bans the percentage of restaurants and bars that allow smoking was close to 100%, with only mavericks like the Mountain Sun Brewery daring to have the ban. A classic case for intervention by the people through their government (note again that even Greeley and Pueblo have supported smoking bans).
To me, smoking bans aren't some "nanny state" plan to get people to stop smoking. Go ahead and kill yourselves in the privacy of your own home, I say. The smokers say this is an issue of their personal freedom, but even under a ban they are free to go to restaurants and bars, while without a ban some places are effectively off-limits to people with tobacco allergies or asthma. I don't see why my freedom to visit bars and restaurants without having a physical reaction should be deemed less important than other people's "freedom" to fill those places up with second hand tobacco smoke.
One of these days, now that California has a statewide smoking ban, I want to get back to San Francisco and enjoy the great Toronado Pub now that it isn't choked with clouds of tobacco smoke.
Here in Denver, we are unlikely to get a smoking ban so long as we have a restauranteur as mayor (although I suppose he could do the Nixon-to-China thing). Interestingly, I met a friend for a couple of beers at the bar of the mayor's own Wynkoop a couple of months back, and I noticed that there wasn't a single person smoking in the whole place, ban or no. Although the employee-safety issue should trump everything, I guess I can live without a ban if the trend against smoking continues to be so strong that the second hand smoke issue becomes a non-issue.
Update: To be clear, yes, the Mountain Sun was totally non-smoking even before Boulder enacted its smoking ban. A rare example of a bar that didn't follow the herd.