I had to double check that it wasn’t The Onion.
Dr seuss certainly had a change of heart later on in his career, (as all intelligent folks i hope would) from my understanding of his still fascinating story of how he came about writing and drawing. Horton hear's a who though was most certainly satirical representation of racism, as you can see his later political newsprint sketches showing what he really felt.
However there is no question how he originally felt about foreignors earlier on in his career and i can certainly see being caught up in a real war, the pull of nationalism is quite strong.
Personally, i don't think it's fair to either dr. seuss nor many of history's most famous authors by viewing them with a modern 20/20 hindsight without understanding the context in which the story was being told. The stories are there to be told, but on the flip side, there's nothing wrong with requesting current teachers to explain about stereotyping and /or prejudices that went on during the period the story was written.