TUCSON, ARIZ. - Until recently, Arizonans could hardly turn on a television or radio without hearing a slightly self-righteous teen voice singling out smoking as a notably unattractive habit – smelly and teeth-staining – as well as an unhealthy one. The riff was catchy, slightly disgusting, and highly effective: The American Lung Association credits the ads with helping to reduce teen tobacco use in Arizona by nearly 7 percent between 1997 and 2000. The US Centers for Disease Control and Prevention even touted the hard-hitting media spots as a national model. But in the end, even widespread acclaim couldn't protect...