I don't think you can compare the Black Panthers to the KKK. While they had their dark side, the Panthers were originally fighting for social justice at a time of oppression and inequality. The KKK were fighting to maintain that inequality and establish supremacy over those who were different.
Having said that, Beyonce shouldn't have brought politics into her performance and the African American community need to stop treating violent losers like Michael Brown and Martin Woods like martyrs. It isn't doing them any favours.
Anyway, I think the bigger question is why the fuck do white Americans even watch this sport and why are all these SuperBowl half time shows so fucking lame?