Spartacus, this question has been a deep one. Why did the Allies, especially America, did not do anything to combat racism in their armies?

[NormanStewart]

The media did a good job covering for his failing health.

Speaking of political matters, accusations of racial prejudice were even in 1940 used for political purposes:

Election 1940: Willkie Deplores Racial Attack (10-13-40)

The Pittsburgh Press (October 13, 1940) Defense Efforts Scored — WILLKIE LAYS RACIAL ATTACK TO DEMOCRATS … Deplores Prejudice, Cites Failure of Efforts To Build Up Arms … By Joseph L. Myler, United Press Staff Writer Albany, N.Y., Oct. 12 – Wendell Willkie charged tonight that the Democratic Party was attempting to “arouse racial prejudice” in the United States and asserted that his criticism of the New Deal had been answered only by silence and failure to build “any defense of any kin…