Although the US had long been drawn into the war by 1943, it is important to be aware of the strength of isolationist sentiment before the bombing of Pearl Harbor. The precise connection between isolationism and the general unwillingness of the US people and government to help refugees, if indeed there is one, is far from clear.  Given the strength and longevity of isolationism in American culture and politics, it far from implausible that there may be a relationship between the two.

A 1943 State Department Review of US Foreign Policy from 1931 - 1941 concluded that public opinion driven isolationist sentiment persisted throughout the State Department, but was not shared by the Secretary of State or the President 1. While no serious historical study should accept this alone at face value we need to also remember that such deep and enduring attitudes, where they existed, were very unlikely to have been broken down within the space of two years.

In a Gallop Poll conducted on October 18, 1937 asked a nationwide sample of about 2000 Americans :

"Would you like to see the United States join the League of Nations?"26% said 'yes' ; 52%'no' ; and 22% had no opinion.

For  discussion of this poll see Leigh, M., Mobilizing Consent: Public Opinion and American Foreign Policy, Greenwood Press, Westport, 1976, p38 - 41.
 

A series of Gallop Polls conducted during 1939 looked at public opinion relating to American involvement in the European War, the specific questions were:

March 1939 - " In case such a war [ German and Italy versus England and France] breaks out, how far should we go in helping England and France - should we send our army and navy abroad to fight the enemies of England and France? " 17% responded 'yes'; 83%'no'.

May 1939 - " In case Germany and Italy go to war against England and France, how far should we go in helping England and France? Should we send our army and navy abroad to fight Germany and France?" 16% responded 'yes' ; 84%'no'.

August 1939 - " Do you think the United States should declare war on Germany at once and send our army and navy abroad to help England, France, and Poland?"  8% said 'yes' ; 90% ' no' and 2%'don't know'.

September 1939 - " What should be the policy of the United States in the present European war - should we declare war and send our army and navy abroad to fight Germany? " 6% said 'yes' ; 94% 'no'.
 

A  nationwide Gallop Poll conducted during the first week of December of 1940 asked Americans :

"If you were asked to vote on the question of the United States entering the war against Germany and Italy, how would you vote - to go into the war ot to stay out of the war?"12% said 'go in' ; 88%'stay out' while 3% expressed no opinion.
 

1. Michael Leigh, Mobilizing Consent : Public Opinion and American Foreign Policy, Greenwood Press, Westport, 1976, 32 - 33