It's closer to proportional rather than disproportional representation in this case. Latinos make up about 30% of Chicago's population, but they're spread out so they wouldn't form a majority of any single compact district, so wouldn't be able, as a community (if indeed it's a coherent community), to send a representative to Washington to represent their views. However, if you connect demographically similar areas, then the community gets representation closer to their actual share of the population.
Of course, we could just use proportional representation outright and achieve a similar result, or elect candidates from multi-member districts and a slate of candidates (e.g. put all of Chicago in one district, and elect the top 4 candidates). But that's a more radical reform that's less likely to happen.
Of course, we could just use proportional representation outright and achieve a similar result, or elect candidates from multi-member districts and a slate of candidates (e.g. put all of Chicago in one district, and elect the top 4 candidates). But that's a more radical reform that's less likely to happen.