The historian Bruce Kuklick doesn't have very good intellectual judgment (as those who've read his work on the history of philosophy in America will know), but he has compiled some interesting stuff in his latest book on "fascism" in American political discourse; an excerpt:

[E]ven at this early stage in its history, fascism functioned as more than a neutral descriptor; it instead acted as a “foul noun of preference” that Americans “deployed … against anyone with whom they disagreed politically.” The most popular targets of opprobrium were President Franklin Delano Roosevelt and his New Deal. At various points in the 1930s, a number of notable figures derided FDR or the New Deal as “fascist,” including liberal philosopher John Dewey (who worried FDR was creating a “police state”), socialist politician Norman Thomas (who worried FDR was beginning to resemble Mussolini), former Republican President Herbert Hoover (who likewise worried FDR was too similar to European dictators), and populist Senator Huey Long (who worried FDR was too close to the business class). But the president was hardly the only one ridiculed in this fashion. As Kuklick highlights, until the U.S. entry into World War II, “everyone called anyone a fascist.”