So, what this says to me is Obama is winning nearly all the black vote, Clinton is winning the majority of the white vote, but apparently only white women are keeping Clinton's campaign alive.

Which is about what I would expect. The nation is still very racially polarized along black/white lines (but far less so concerning other races, who are voting for both candidates), and only white women seem to hold it together to make a significant voting bloc, as women of color are dividing their votes.