Since Huey Long is so often mentioned in connection with American fascism, it might be worthwhile to quote the judgment of James Weinstein: "Of all the 1930s radical politicians, Louisiana Governor Huey Pierce Long Jr. was by far the most successful. A charismatic figure, he is often mistakenly remembered as the first American dictator or the first great native fascist. As his biographer T. Harry Williams wrote, Long was in fact a uniquely democratic politician who had nothing in common with the dictators except their popularity. As a consistent champion of working people and an implacable enemy of the corporate monopolies and Eastern banks, he commanded one of the largest mass followings in the country. "
https://books.google.com/books?id=pYHeUBZzCDYC&pg=PT105
That being said, there is no way that Huey Long is getting nominated in 1932, even if FDR isn't around. Remember the two-thirds rule--there would be way more than one-third of the delegates, especially from the Northeast, who would think Long too radical (many felt the same even about FDR).
Indeed, the striking thing about 1932 was the
weakness of radicalism of both the left and right. As E. B. White wrote, 'People are in a sad, but not a rebellious mood."
https://books.google.com/books?id=AXCnQaJCtQ4C&pg=PA435