Interesting points, legalsea.
Let me ask you this: Is a privately owned restaurant, that is open to the public, a private building or a public building??
And as an owner of a restaurant, or any other business establishment, do you have the right to, say, refuse service to certain people, like blacks, women, Muslims, Jews, etc?
I'm just asking, because it seems to me that just because you "own" a business, doesn't mean you can do whatever you want to in it.
I think that privately owned land upon which there is a building (such as a restaurant) that is open to the public for business purposes is, nevertheless, privately owned. It does not turn into a public building or land, which I interpret as being owned in common by the people. State parks, etc.
Of course, just because you own land does not mean you can do whatever you want to in it. For instance, laws against theft, murder, arson, etc., still apply to actions done on private property.
As for discrimination: I distinguish between discrimination against a person due to his or her race, religion, sex, national origin, etc., (banned by the Civil Rights Act of 1964) versus acts of the local governments that tell private property owners that they cannot allow smoking on their property. They do not correlate.
In other words, the restaurant owner is allowing all, smoker or non-smoker, onto his or her premises. The owner is not discriminating against anyone or excluding anyone. Smokers and non-smokers have a choice concerning entering the property.
Recall, while the Civil Rights Act defined public accommodations (private property that is open to the public at the invitation of the owner), it did not lessen the owners ultimate right in the property. In other words: you, as an individual, sitting on your private property (with no building on it), may exclude people from your said property based on race, sex, etc.
However, when you expressly open your property to the public, then the Civil Rights Act mandates that you allow all of the public access, save in very narrow circumstances. If you build a fancy restaurant on your private property, but do NOT open it to the public, then you may discriminate.
We still have plenty of private country clubs in this country that do not allow membership to people of certain races, religion, etc. They are not open to the pubic, hence they may discriminate.