Perusing a proposal (PDF) from Action on Smoking and Health for a government-imposed surcharge on smokers, Michael Siegel notes this revealing passage, explaining why a surcharge on fat people is less feasible (emphasis added):
Fewer than 20% of adults are smokers, and only about 13% smoke daily, while about 33% of adults are obese, and another 33% are classified as overweight. Thus the number potentially affected by a smoker surcharge is far smaller, and, because smokers are concentrated largely in the lower socioeconomic classes, they are less likely to be able to effectively object. A surcharge on the obese would arouse objections from a much larger segment of the population, including many people with considerable influence.
Siegel, a public health professor at Boston University and prominent anti-smoking activist, is offended by ASH's candor:
This demonstrates that to ASH, this truly is class warfare. It is not about health or reducing health care costs; instead, it is about declaring war on a particular social class that ASH apparently abhors.
Can't it be both? The anti-smoking movement has always had an ambivalent attitude toward smokers, who are seen both as victims, tricked by tobacco companies into a deadly habit they cannot escape, and as villains, irresponsibly imposing their fumes, ashes, butts, and health care costs on their fellow citizens. Accordingly, they must be helped, but they also must be punished. Policies that make smoking more expensive or less convenient, such as cigarette taxes, smoking bans, and the surcharge ASH is pushing, can be defended as serving both goals.
As Siegel notes, ASH is so eager to promote the surcharge (based on the erroneuous argument that smoking imposes a net burden on taxpayers) that it contradicts anti-smoking dogma (and its own position in tobacco litigation) by declaring that people can give up cigarettes any time they want to:
Most people see buying and using cigarettes as a habit or a choice, thus fitting the criteria for a user fee. Although there is evidence that for many people smoking involves addiction, the addiction is to the drug nicotine, not to the act of smoking itself, which is a behavior.
Because those who desire to can easily ingest nicotine from nicotine gum, nicotine patches, nicotine spray, and nicotine inhalers, their decision to ingest it by smoking rather than by using nicotine replacement products is a choice. Since it is a choice rather than an addiction, disease, or health status, it is fairer to impose personal responsibility for the choice by making smokers bear at least a small portion of the huge costs their choice imposes on the economy and the health care system.
Siegel correctly notes that cigarette smoking is a complex habit that cannot be reduced to nicotine, as indicated by the low success rates of people who try to replace cigarettes with pharmaceutical products containing the drug. But he makes a common error by insisting that smoking can't be a choice because it's an addiction. Likewise, ASH, which heretofore has said smokers should be able to recover damages from cigarette manufacturers because smoking is not a voluntaruly assumed risk, now says smoking can't be an addiction because it's a choice. As writers such as Thomas Szasz, Stanton Peele, and Jeffrey Schaler have long argued, one concept does not preclude the other. Understood as a strong attachment to something that provides pleasure or relieves stress, addiction leaves a large role for choice, as demonstrated by all the world's nonsmokers (many of whom have tried cigarettes without ever consuming them regularly) and ex-smokers (who consumed cigarettes regularly yet managed to stop, typically without any kind of formal treatment).
The disease model of addiction, which portrays smoking as something that happens to people rather than something that they do, is consistent with the mixture of sympathy and disgust that smokers elicit from public-health paternalists. Like carriers of bubonic plague, smokers deserve compassion, but they also need to be ostracized, for their own good and ours. A similar mixture of sympathy and disgust is apparent in the anti-obesity movement: These poor porkers can't help themselves, so we have to, whether they like it or not. Any cost they suffer as a result of our interventions will help them in the long run by encouraging them to shape up. But they also pretty much deserve it, for being such slothful, repulsive gluttons. As with smoking, there is a class angle, since in America the fattest people are also the poorest (an amazing development from a historical perspective). But as ASH notes, anti-fat measures are politically tougher, since the government says most of us—including plenty of affluent, influential people who can "effectively object"—weigh too much.