Harding, our first Black President?

I came across this interesting read in the Times. I am putting it up for informational purposes under the category of:
"Things that make you Hmmmmmmm."

Will Americans vote for a black president? If the notorious historian William Estabrook Chancellor was right, we already did. In the early 1920s, Chancellor helped assemble a controversial biographical portrait accusing President Warren Harding of covering up his family’s "colored" past. According to the family tree Chancellor created, Harding was actually the great-grandson of a black woman. Under the one-drop rule of American race relations, Chancellor claimed, the country had inadvertently elected its "first Negro president."

It goes on for a bit but is interesting non the less.