I'm reading a book on Charles Lindbergh, thinking about his support for non-interventionism leading up to World War II. The America First Committee has a number of prominent names associated with it, so I was led to wonder what their motivations were.
It's possible that these people were taking a principled stand against intervention in foreign conflicts (such as might be expressed these days about the conflicts in Syria, Iraq, Yemen, or Libya), or it might be that they were hoping that Nazi Germany would prevail in its wars.
Clearly the answer could be different for different people. I don't know if the movement has been studied in any depth. (Reflections on whether a question such as this can be answered from historical evidence would also be welcome.)