Kammala jumla mai zuwa: Wani mai gwagwarmayar Democrat na dogon lokaci, Willkie ya canza rajista na jam'iyyarsa zuwa Republican a ƙarshen 1939. Bai gudu ba a cikin 1940 na farko na shugaban kasa, amma ya sanya kansa a matsayin wani zaɓi mai karɓa don yarjejeniyar da aka kulla. Ya nemi goyon baya daga wakilai marasa biyayya, yayin da magoya bayansa - da yawa matasa - suka yi himma wajen inganta takararsa. Yayin da sojojin Jamus ke ci gaba
ta hanyar Yammacin Turai a 1940, 'yan Republican da yawa ba su so su zabi wani mai rabuwa kamar Thomas E. Dewey, kuma suka juya zuwa Willkie, wanda aka zaba a kuri'a ta shida a kan Ohio Senator Robert A. Taft. Tallafin Willkie don taimakon Burtaniya ya cire shi a matsayin babban mahimmin abu a tserensa da Roosevelt, kuma Willkie ya kuma goyi bayan shugaban a kan zaman lafiya. Dukkanin mutanen biyu sun dauki matsayi mafi mahimmanci a ƙarshen tseren. Roosevelt ya lashe wa'adi na uku wanda ba a taɓa gani ba, yana ɗaukar jihohi 38 daga cikin jihohi 48.