Smokers don't understand how much the byproducts of their habit are an imposition on the rest of us. Secondhand smoke makes the eyes water and itch, the nose run, causing a scratchy throat and shortness of breath. And it also kills.
Unless I enter an establishment that has a warning posted on the door that says "Tobacco smoking permitted inside", there's no way I consent to exposure, least of all by walking on the public sidewalk, any more than I consent to being sprayed with chlorinated hydrocarbons or dusted with cocaine. Whether or not it's a byproduct of someone else's pleasure doesn't change that.
What would the ideal smoking law do? It would prohibit smoking in public, including on the sidewalk and on outdoor patios, except in places--enclosed rooms and courtyards--where one receives warning before exposure. And it would do something for those poor children, who couldn't possibly have consented, who are exposed to smoke in the home and go to school reeking like old ladies. Our laws are backwards; we can't legally encourage healthy alcohol consumption by giving teens a glass of wine with dinner, but we can fill childrens' lungs with tar and ash.
Not wanting to make the perfect the enemy of the good, I'm taking a stand for the right to stop a proverbial swinging fist where my nose begins and voting for Proposition 201. This despite it being put on the ballot by a group of busybodies including the American Lung Association which shouldn't be involving itself in legislation and politics, despite it raising the tobacco tax by two pennies per cigarette pack, despite it requiring, ridiculously, nearly every place where smoking is prohibited to post "No Smoking" signs, despite it exempting the outdoors, and despite it not providing private property owners to opt out.
Proposition 201 prohibits smoking inside all enclosed public places and places of employment, explicitly excepting outdoor patios, tobacco shops, private vetarans' and fraternal clubs, and hotel rooms.
A lot of my Libertarian comrades will find my position hard to swallow, some because in their quest for a grand unified theory of politics and ethics they have come, bizzarely, to the conclusion that what they call "property rights" (bearing only coarse resemblence to the actual institution) are somehow the most fundamental, and some due to difficulty separating the concepts of public and private space and public and private property. I'll offer my apologies now to those who've been pointing people here as though I've been presenting the definitive LP position on the issues (Sorry, Dave!) but I stand by my positions as not only correct, but liberal (libertarian), too.
Where negative externalities are involved, the law always has to balance rights. Prop. 201 is a minor and equal imposition on the rights of business owners, and the tax it establishes is flat-out gratuitous, but the current laws favor too much the right of smokers to indulge their habit over the right of the rest of us to not have noxious, carcinogenic irritants forced on us without our consent. Let's take a step in the right direction now; a sidewalk smoking ban and an opt-out for property owners can be added later.