Oh, she could very well run on the Green line or as an independent, but she wouldn't win the Democrat nomination. There's a strong possibility she'll be the Green candidate for Prez (~25%, I think), which would be a godsend to Bush.
I'd probably vote for Oxendine myself, though either Kingston or Collins would be good. How much do you want to bet that the Democrat primary will segregate between white voters and white candidates and black voters & black candidates? I'd be willing to bet that if more than one black candidate runs in the primary a white candidate will win.