State's rights is a separate issue altogether. But someone who supports states right can look at a law like this, disagree with it, but not care all that much because it is not their state.
State's rights allows more people to live in the situation they prefer. I disagree with this law, but I don't live in that state so it doesn't affect me. It's far superior to have such a law at the state level than at the national level because of that. I would oppose such a law in my own state, but I only argue about it's asinine nature when it is employed in another state.
And, for the record, I smoke in my car, but never while my son is in the car. I agree with not smoking in a car that contains children, I disagree with making it a law. If we are going to pass laws like this, we need to start with real problems that cause far more harm than second-hand smoke does, such as fast food being fed to children.
Look at all the fat little ****ers running aro... scratch that, waddling around these days. The little weeble wobbles are too damned fat to run.
That's a hell of a lot more unhealthy than second-hand smoke is.