I find this argument from Jon Chait pretty compelling:
[in 1964,] social psychologists Lloyd A. Free and Hadley Cantril concluded...[that] Americans are ideological conservatives and operational liberals. Everybody's for less spending and regulation in the abstract. When you try to translate that into specifics--say, lower Medicare benefits or looser standards on pollution--voters run screaming in the other direction.
Any debate that takes place at the level of ideological generality, then, inherently favors the right. Liberals can try to come up with slogans of their own. For instance, Clinton's "Community, Opportunity, Responsibility" mantra was one of the better efforts. But that brings you back to the problem of nobody understanding what you believe in.
