Searching through Google for nothing in particular, I came across this page from Public Opinion Polls on Japan by Arthur N. Feraru, Far Eastern Survey, Vol. 19, No. 10 (May 17, 1950), pp. 101-103. This is part of a summary of surveys into views of Americans regarding Japanese and their internment during World War Two.
UPDATE: Thanks to Peter at Friendly Noises for providing me with the text of the rest of the article regarding American attitudes towards Japan during and in the aftermath of World War Two. The story continues in my next post.
In December 1942, according to a poll by Gallop, 97% of those from California, Nevada, Oregon, Washington and Arizona approved of the relocation of them to camps, 2% opposed, and 1% were undecided. Only 29% approved of their free return to the West Coast after the war, 24% would allow US citizens only to return, 31% would allow none, and 16% were undecided. In addition, 69% would be unwilling to hire Japanese servants after the war, and 58% would boycott Japanese stores.
On a nationwide basis, 35% approved of their free return to the West Coast after the war, 26% would allow US citizens only to return, 17% would allow none, and 22% were undecided.
In another survey conducted in December 1944, when asked what they thought should be done about Japan after the war, 13% favoured killing everyone, 33% favoured the breaking up or dissolution of Japan as a political entity, 28% supported supervision and control, and only 8% favoured re-education and rehabilitation.
Talking of history, it seems there is also a book What Japan Thinks from way back in 1921, which might be interesting to try to get my hands on.