Americans didn't elect him because they believed anything he said. They were basically paying as little attention as they possibly could and have no idea what he has ever said about anything - if you go and read interviews with swing voters they just have entirely imaginary ideas of what he's like.

The only thing they remember is he was president in 2019. They don't reliably know who it was in 2020/2021 though.

(I think the fixed-term strong presidential system is essentially unfixable here. The country needs snap elections.)