Yes. Generally the people who say they can't believe that "racism" has a very narrow definition that implies that only a "dominant" demographic can be defined as racist, but this definition seems almost exclusively academic and unhelpful. In that broader definition of racism of prejudice or hatred based on race, absolutely black people can be racist, as can anyone else.
Now, if'n ya wanna talk about institutional racism, then yeah. Black people prolly can't be racist. The point, though, is that nobody who should do so ever differentiates.
Benedict Arnold 