This is tricky, because the very interesting Christian Front movement has - by being corporatist nationalists in outlook - ties to the radical right and the left opposition in this time. Gerald L.K. Smith and Father Coughlin, big representatives of Christian Nationalism of the time, had ties to the left-associated Spread Our Wealth society of Huey Long. Spread Our Wealth, in turn, shared stages and media attention with Norman Thomas' Socialists and with activist former general Smedley Butler.
And the Christian Front are the most insidious cryptofascists of the time because they were using popular, populist causes to push antisemitism.
Anyway, a lot of the same right-left mixing of Spread our Wealth and the Progressive Party of the time would again occur in America First, the anti-war group which had both fascist sympathizers and left wing peaceniks.
Besides Christian Frontists, who were anti-semitic but not anti-Catholic, there were genuinely fascist and nazi groups like the German American Bund and the Silver Legion that were both, and the KKK (which existed all over, not just in the South) which were also both.
On the neither anti-semitic nor anti-catholic area you have the American Liberty League, implicated in the Business Plot against FDR, who had been channeling money into the American Legion to turn it into a "glorified strike-breaking outfit" as Butler put it; with the idea being that pro-corporate Democrat Al Smith (a Catholic conservative rejected by KKK-affiliated Southern conservative Dems back during his presidential run) would make a great new leader to preserve Wall Street's power and undo FDR's changes.
As for the Left, you have the Progressives and Farmer-Labor in the Midwest (and Progressives in California); Spread Our Wealth has a lot of supporters nation-wide; the radical Left is thriving if still small as well. Besides the class-collaborationist AFL you have left-wing radicalism in the unions being organized by the Communists' Trade Union Unity organization, the Trotskyists are embedded in the Congress of Industiral Organizations, and the Socialists have been working with unions and other groups for generations.
A big question about the Left would be whether Lovestone, the American exceptionalist, is running the Communists when the war breaks out or William Z. Foster the Stalinist.