The American polity, like a magnet, is polarized because it has two poles, for which the Republican and Democratic parties are rough proxies. Why does the United States have two political poles? Because it has two major political tendencies. Goldberg and Greenberg write of polarization, but they do not believe in it. They do not understand the United States as having two legitimate competing political camps but as suffering from a kind of infection in the form of the Republican party, which inhibits the normal and healthy — meaning Democrat-dominated — political life of the United States. They believe that something they call the “New America” has an unquestionable natural moral right to rule and that the Republican party is not a competing pole but a blockage. To write as Greenberg does that the Democratic party is to be liberated by the practical elimination of the Republican party, and hence able to operate unencumbered, is to embrace not only the end of the GOP but the end of ordinary political opposition.