So you are saying there is a direct equivalence between white nationalists and black nationalists? I'd love to hear this - ok, I'll take a stab.
Both groups are racist - white nationalists hate black people and black nationalists hate white people.
The KKK grand wizard is a racist, so is Louis Farrakhan.
Both groups use racist language, both when talking about members of other races and members of their own race whom are deemed 'traitors'.
Both groups take examples from individuals and then apply it to the whole group.
So, just because some black people are violent and/or leave their girlfriends to be single parents ... in white nationalists' minds, 'black people are like that.'
And just because some white people are undoubtedly racist ... in black nationalists' minds, 'all white people are racist.' (Don't believe me? - check out what BLM supporters say.)
Some white nationalists want a white ethnostate. Some black nationalists (e.g. Nation of Islam) want a black ethnostate, or at least they did back in the 60s and 70s.
In fact, the leaders of the Nation of Islam and the KKK were in talks with each other at one point - both believed in racial segregation and ethnostates.