FDR didn’t have anything resembling a mass movement.
His economic response to the GD was starkly similar to Obama’s. Bailed out the banks, gave them $1bn, let big corporations kept the power to fix price in anti-monopoly legislations. What he had was the ability to keep the people on side with his fireside chats, and an uneasy yet still effective coalition of Old South Democrats and the northern business type he represented, and it was of little surprise that black and Native American people saw none of the New Deal’s benefits, due to this coalition.
People love to bring up ‘I welcome their hatred’, but most of his New Deal accomplishment had already been done before that speech. The rich rules America and the only way to break that would be pitchforks on the street, not elections.