Depends on the state. I was surprised to see "no ban" for Virginia on the map, because I haven't seen indoor public smoking, anywhere, since moving here in 2011. Apparently it's allowed in places that have built "structurally separated and ventilated rooms" but nowhere I've been actually does that... I'm sure it's out there but certainly not "common".

When the ban was first instituted in Virginia there was a lot of pushback from restaurant and bar owners, but not many were willing to put their money where their mouth was and invest in separated HVAC systems. For the most part the handful that exist now are smoking-focused, e.g. cigar and whisky bars, which just aren't that popular any more. The one bar I remember well never did better business than the non-smoking bars around it and closed after a few years.

While it is common in some bars, it's no longer common in restaurants at all. I've lived in Texas for 5 years and haven't once seen a restaurant with a smoking section. It's usually outside if at all.

I have nothing against bars allowing smoking if they want, but having grown up with smoking/non-smoking sections I'd never willingly visit a restaurant that allowed smoking. I like to actually be able to taste the food.