You mean like how these guys did?
I won't say that being white doesn't have some degree in Em's success (even he says that) but I can name dozens of white MCs, some that had a legend's co-sign (Da Knuckleheadz), underground love (El-P), hood talent (Millkbone), celebs with a built-in audience (Brian Austin Grren), played a starring role in a hip-hop movie (Kamron from Young Black Teenagers, who were also co-signed be Chuck D), cats that held they own with modern day legends (Bubba Sparxxx) & even those that paved their own way in hip-hop (Insane Clown Posse). None have been half as successful as Em.
Em has paid his dues in hip-hop & should be rightfully respected.