By Julian Zelizer
Americans no longer expect virtuous protagonists. For almost two decades, Americans have been tuning in to cheer on the antihero on television, on acclaimed series from "The Sopranos" to "Breaking Bad" -- and dozens more. We watch characters who do whatever is necessary to make things happen. They are not pleasant, they are unethical, they are mean and nasty, and they cheat and steal to get their way. Some even resort to torture and murder. Yet we have urged them on with our fandom and our excitement.