Nigger means black, from the Kaffir word Niger ... whats the problem calling a black a nigger 
EDIT: It's also Latin for black.
Latin
A black person/A niger homo
A black man/A niger
Obama is a black man/Obama est niger

EDIT: It's also Latin for black.
Latin
A black person/A niger homo
A black man/A niger
Obama is a black man/Obama est niger