Is, or was, liberalism the norm in this country?

In his earlier years,  Lionel Trilling wrote for and in the liberal tradition, explicitly rejecting its rivals; cf. the preface to his The Liberal Imagination, 1950 (emphasis added to the much-quoted last line):


"In the United States at this time Liberalism is not only the dominant but even the sole intellectual tradition. For it is the plain fact that nowadays there are no conservative or reactionary ideas in general circulation. This does not mean, of course, that there is no impulse to conservatism or to reaction. Such impulses are certainly very strong, perhaps even stronger than most of us know. But the conservative impulse and the reactionary impulse do not, with some isolated and some ecclesiastical exceptions, express themselves in ideas but only in action or in irritable mental gestures which seek to resemble ideas."