What’s American Liberalism… Exactly?

For an interesting discussion about American Liberalism, I suggest going here. The post is based on this article at the New York Times, by Patricia Cohen. She writes that there is a discussion going on in American Liberal circles, about the essence of Liberalism, what policies Liberals favor. Should Liberals talk about morality in society? What about foreign policy? Should the US adopt an interventionist foreign policy, or more of an isolationist one?