Because you need to define it in ways that are easy to understand and make sense without being a fucking mouthful and potentially offending them.
Let's try this instead:
"The violent criminal asshole element of the chicago region that create no-go zones for cops and love to start riots and murder each other over petty bullshit while desperately begging the democrats for social aid to support their divorced families and children on wellfare for broken homes because the fathers are mostly felons at this point or on the run from the law, so we're appealing to anyone left who still has the right to vote."
... Sounds a lot worse and is harder to deal with than saying "the black vote in chicago."
