WWII homefront- crippling race-related strikes
What factors would be required on the US homefront during WWII for there to have been racially-motivated strikes, by white workers virulently against working alongside blacks in wartime industries, to such an extent that the US war effort was significantly affected ? OTL there were such incidents as in 1943 in Mobile and Birmingham, Alabama IIRC, by Southern whites not wanting to work alongside blacks in the shipbuilding industries, and 1944 around D-Day in Philadelphia, Detroit and Cincinnatti, where many white workers staged hate strikes to protest the hiring or promotion of blacks. Of course, there was also the 1943 Detroit riot which exposed the tremendous racial tensions between blacks and whites over jobs and housing in the crowded wartime motor city. How could such racism in the wartime workforce have developed to the extent of seriously limiting American munitions production ? What about e.g. if the Nazis were able to infiltrate some sorta ABWEHR team into the country to incite and co-ordinate racist hate-motivated strikes thruout American industry ?