In OTL, FDR contracted polio while on vacation at Campobello Island in New Brunswick. He survived and ended up totally paralyzed from the waist down for the rest of his life. In "this" timeline, FDR has complications which paralyzes his lungs and he asphyxiates. He never becomes president, putting another Democrat in charge, which has severe repercussions for the U.S and the world, as it slowy falls from democracy into totalitarianism, all because of the death of one man.