There’s no defending this practice. Forcing children to breathe tobacco smoke in any environment – home, car, wherever – can damage their health, sometimes permanently.

The only argument against the legislation is a purely libertarian one: that government ought to give citizens maximum leeway to make their own decisions, even if they’re the wrong decisions.

But don’t bet on that argument to carry the day. The public’s growing impatience with irresponsible smokers guarantees that more such laws are on their way.