There are two contexts in which this word can be used, the first being the racist context, the second being the specified context.
Racist: A racist would use this word to describe any and all persons of African decent, reguardless of social status, income or religion.
Specific: Someone using this word in the specified sense believes that there are good and bad people of every race... that there is a difference between a black person and a nigger. (Black person: hard working honest contributing citizen. Nigger: Some scum bag that is perfectly healthy, however, sits at home all day collecting my tax dollars via welfare, and uses the money that he/she gets to buy luxury items such as a ridiculous gold chain with a medalion the size of a manhole cover, or, like the "niggers" where I come from, use this welfare money to buy crack on a day to day basis, instead of getting a fucking job and making an honest living.