The hysteria surrounding Mayor Bloomberg's large soft drink ban is fairly ridiculous. Really, my biggest problem is his approach; a ban on large drinks will be less effective than a hefty tax on soda by the ounce. Not a ton of people agree with me on this: Americans seem to think that what starts with a super-sized soft drink ban will logically and inevitably end with a nanny-police state. This assumes that we have no capacity for restraint or rational governance, which is ridiculous.*
Most people already accept that the government has the right to intervene in some situations. If a parent gave a child ice cream for dessert every night, we might think the child spoiled. If a parent fed their obese child ice cream for breakfast, lunch, and dinner, we would be thinking about calling social services. If a parent was giving their child alcohol or cigarettes, we would definitely call social services. Many of the loudest voices criticizing mayor Bloomberg also firmly in the anti-drug legalization camp. If a police state is scary, why are we incarcerating people who smoke marijuana?
Next, consider that while trying to regulate soda slightly infringes on the rights of people who drink soda, being obese and relying on government-provided health care greatly infringes on the economic rights of people who pay taxes. If we lived in a nation where everyone had to sleep in the bed that they made for themselves, I would be more sympathetic to libertarian extremes. As it stands, all Americans are guaranteed access to health care in emergent situations and all Americans are guaranteed health care at age 65. Your right to drink soda and be unhealthy needs to be balanced with my right to be free from overwhelming tax burdens.
It is very important to remember that government is part of the reason we got here in the first place. There are government subsidies for industrial agriculture, corn, meat, and processed food. This artificially cheapens the price of the most unhealthy types of food; it is literally the case that the federal government pays Americans to eat at McDonald's (indirectly). No wonder why we have an obesity crisis! It is not libertarian or conservative to be a defender of a market so distorted by government influence.
The obesity crisis is getting worse, and health care costs are literally bankrupting the United States. Are there more ideologically pure ways to fight the obesity crisis than to tax soda? Possibly; but none are so simple to implement, likely to be effective, and politically realistic. Smokers consume a lot of health resources, and we all agree that smoking is a bad habit. Not a ton of people are upset about the fact that we tax cigarettes. Soda should be similarly considered.
On an aside, from a purely speculative health standpoint, let me also say this: if you forced me to either drink 3 cokes every day or smoke 10 cigarettes, I am inclined to think that I would be better off smoking the cigarettes. It would be interesting to read a study that tried to compare the two to see which is worse for health.
* Unless Republicans are in charge