IIRC, this was set in the postwar south, so the main character was a free man. 8 saw it as a small child and loved the song Zipadeedoodah- race and skin color meant nothing to me, if anything, at the time I had just lost my beloved grandfather and the main character reminded me of him, and the stories reminded me of grandma, who being from southern Missouri had a pretty thick hillbilly accent and was quite a storyteller.
I think the leftist objection was exactly that- they want to perpetuate fear and segregation so they can continue their successful divide-and-conquer strategies. It is their bread and butter. White kids who fell in love with the cartoon wouldn’t be afraid of or hate black people, and would see our commonalities rather than the differences the Democratic Party has for so long worked to stoke, highlight and exploit.
There was a lot of injustice in the South after 1877 and before 1956. But not all whites were Klansmen or subscribed to white supremacy. There were decent people, both black and white.
During this period, the South, with few exceptions, was a one party Democrat region.