Well, there was the supposed Business Plot in which Smedley Butler claimed a group of American businessmen offered to make him 'Secretary of General Affairs' had he participated in a coup against Roosevelt, but there is serious debate over whether or not that plot was legitimate.
Fascism attacks the legitimacy of the ruling government and it's ability to rule, so it would take something on the scale of a massive break down in social order before a large group of Americans start believing fascism to be a legitimate replacement for democracy.
Onto your candidates...
He was a Nazi, not a fascist. He was seen by the American government as an agent of the German government (which he was). I doubt many people would flock to him.
Maybe. He was a anti-Semite and a eugenicist, but I don't think he was a 'fascist'. He was more of a isolationist than a fascist. It just so happened that he wanted to be a isolationist from a war involving fascist dictatorships
This guy has more legitimate credentials than Kuhn or even Lindbergh. He was a religious figure, which could tap into the hearts of Americans more so than any other leader, though I should point out this guy was hated by the Vatican for his anti-Semitic screeds, so some people might feel apprehensive about supporting him.
Well, he cracked down upon the Bonus March without so much as a second thought under Hoover's orders, so I could definitely see him as the leader of a fascist government. He had a rough relationship with his commanders in chief, especially FDR, so I can see him having no love for parliamentary democracy.
Don't make me laugh. The guy was a loony, not to mention a fundamentalist Christian. I can see him being friends with Coughlin, but I think even Coughlin would want to keep Pelley at arms length.