America was isolationist until they were dragged kicking and screaming into the war. Churchill was regularly crossing the Atlantic to beg Roosevelt to try to garner enough support to join the war. The American people did not care. The majority were against joining the war.

All the same today, The majority of Americans either support MAGA or are indifferent. Short of some great personal injury such as a Pearl Harbor type event, Americans will continue to be as they are.

The idea that Americans were anti-fascist heroes is propaganda. They were only angry that they got got by Japan.