Lupe says that there wouldn’t be any ghettos, no crack and no gangs if the social disparity between classes didn’t exist. The founding of the Crips occurred because of the falling out of the Black Panthers and similar Groups. The Crips would never of had to rise to fill that gap left in black society if there wasn’t social inequality. Likewise, the Bloods would not have had to come into existence to keep the Crips in check.
Also, This line also has somewhat of a hidden meaning to it. A lot of mainstream media (i.e. Bill O'Rreilly) accuse hip-hop/rap as though it is causing problems in America by glorifying violence. Lupe disagrees and is saying here that it is not the rap that causes the problems, but the problems that cause the rap. Without racism and horrible things happening to black people, there would be no gangsta rap music like there is today (violent, degrading to women, et cetera.)
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