How the KKK, with its iconic fiery crosses, is spiking in activity, adopting mainstream politics, and forming alliances with skinheads and neo-Nazis.

Inside four neo-Nazi groups pushing white separatism, blaming societal ills on minorities, and rallying around Hitler's ideology to gain political influence.

Skinheads are the fastest-growing hate group in the U.S., leading the White Power movement with violent tactics; law enforcement fights back against their rise.

The New Black Panther Party and other Black Nationalist groups are redefining Black Power, inspired by the legacy of the original Black Panthers.