The tar baby folk tale is the origin of the term and not racist.

that's a connotation that has emerged in use in the 20th century from the story but the story itself, the origin of the term and the metaphor, is not racist.

The term, in fact, originates from African-American folklore, much of which was transferred from black servants to white children and then generally disseminated throughout the culture without a racist connotation.

It picked up that connotation to the extent that it can be used to refer to an African-American, but as with a lot of other terms that double as epithets, it does not necessarily imply it.