While there FDR was liked by the public, thought-out his terms there were people who viewed him as a dictator/monarch (mainly republicans but also industrialists/capitalists) who was undermining the idea of a democracy with a rotating head of state. These ideas go all the way back to Washington's decision not to stand for a third term.

After the war there was enough support for these areas (perhaps also by the worry about the effects of being in office so long) for the 22nd amendment to be passed.