In a scenario where FDR and Huey Long are butterflied away (or at minimum delayed from becoming Presidential nominees), the challenge is to have a Democratic President from the late-1920s to early-1930s onwards, who unlike OTL FDR in 1933 refuses to recognize the Soviet Union* and also manages to either get the US out of the depression within 2-5 years without a New Deal analogue.
*- It could be the case that a later ATL FDR or similar Democratic Presidency would end up recognizing the Soviets