Here is my contribution:
To some extent I deal with the issue of fascism and the New Deal in my book FOR THE SURVIVAL OF DEMOCRACY: FRANKLIN ROOSEVELT AND THE WORLD CRISIS OF THE 1930s. Sure, there are superficial resemblances. The early New Deal may look like an attempt at an American version of the European corporatist state, an entity often identified with fascism. New Deal work relief programs sometimes appear to have a rough similarity. Compare, for example, the Civilian Conservation Corps to the Nazi youth work camps, or the American public works programs to Hitler's. Or the upsurge of patriotic nationalism in America to German or Italian nationalism. Roosevelt himself could at times seem dictatorial, and he may well have taken office with a sense that the United States needed strong leadership and organization of the economy vaguely along corporatist lines.
But enough! We can only go so far with this, and it is not much of a distance.
Germany and Italy were fundamentally authoritarian societies; the United States was liberal-democratic to the core. Moreover, it seems to me that the corporatist state (of which one could find many traces in the democratic Great Britain of Stanley Baldwin and Neville Chamberlain) does not constitute the "essence" of fascism. As others have pointed out, fascism is a fuzzy theoretical concept, but about all versions have a few things in common--hyper-nationalistic and racialistic imperatives, contempt for democratic government and liberal values, exaltation of an absolute leader, and respect for brute force. To put not too fine a point on it, fascism in the 1930s was more about rule by thuggery and gangster values than about "corporatism."
The counter-example of the United States is telling. The New Deal failed miserably at controlling the economy, and at bringing economic recovery. A relatively small amount of PWA spending went to the Navy, but in the main the Roosevelt administration was unsuccessful (to the extent it even tried) at building up the armed forces in the manner of Hitler and Mussolini. Mainstream American nationalism during the 1930s was centered on liberal and democratic values and heavily stimulated by revulsion against Germany and Italy. Its major strains revived the reputations of such heroes as Jefferson, Jackson, and Lincoln while celebrating America as the democratic land of the free.
As for Roosevelt himself, he made mistakes, overreached for power at times (court-packing and his original executive reorganization plan), and erred grievously in his insistence on attempting to prosecute Andrew Mellon for income tax evasion. In such instances, he was slapped down, either by Congress, or in the Mellon case by a grand jury that refused to indict. That said, compare Roosevelt's popular leadership style to Hitler's or Mussolini's, and we are down to a creature that resembles a 10th cousin several times removed. True, he and Hitler used radio effectively, but the style and content bear little resemblance.
The New Deal had no black shirts or brown shirts terrorizing opponents, no system of arbitrary arrests and concentration camps, no identification of national greatness with foreign expansion and conquest. Roosevelt accepted the norms of democratic politics, however much he may have chafed under them at times.
Finally, a word about John Garraty's important and much-misunderstood article on the New Deal and Nazi Germany. Garraty's work was pioneering and suggestive--a major piece to my mind. At about every third or fourth paragraph, however, he made it clear that he was not accusing Roosevelt or the New Dealers of dictatorial ambitions. He fully understood that the resemblances he addressed were issues of technique and style rather than substance. It is worth rereading even by those of us who got that point the first time around, and should be mandatory for those who have not.
Alonzo L. Hamby