A short explanation of demographic change in Cook County:

Cook County is still growing in population; it added 271,674 residents in the 1990s, more people than any other Midwestern county. As goes Chicago, so goes Cook — white population declining (Cook: 57% in 1990, 48% in 2000), black population steady but slowly trickling outwards, Latino and Asian populations growing and more than making up for the white decline. The region’s population is still growing, but out-migration and aging are slowly reducing the number of whites.

It’s the same white flight as before, although it’s happening nowhere near as quickly as in the ’70s or ’80s — and now the flight is more to the nation’s suburbs, the South and West, than to the region’s suburbs. Strong NIMBY sentiment to the north, northwest, and west has actually had an effect on growth at the fringe; the only sector in which sprawl is welcomed is in the southwest.

Pretty dramatic racial succession continues at the city’s northwest and southwest edges, in the south suburbs, and in the near west suburbs all the way into DuPage. Belmont-Cragin, Cicero, Berwyn, Little Village, Back of the Yards, Ashburn, and Harvey, among many other areas, are experiencing fast-paced succession right now. Oak Park, Skokie, and the near north suburbs are undergoing slow-motion white flight, but the trendline is still clear: whites are leaving, replaced by Latinos (mostly), Blacks (sometimes), and Asians (rarely). White population growth is in the city’s Yuppie Belt and in the far suburbs.

The other side of the story is immigration: a surge of mostly Latino immigrants is filling the northwest and southwest sides, but also spilling into many Cook County suburbs. Asian immigration is fairly well dispersed, but explains some of the declining white population in the near north and northwest suburbs.

The change in Cook’s demographics are a large factor in why Illinois has tilted Democratic. City Democrats and far-suburban Republicans balance one another out, Downstate is divided, and the near suburbs hold the balance. As the Cook suburbs have gone Democratic, they’ve taken the entire state with them. As recently as summer of 2000, Illinois was still considered a swing state.

(A rather depressing side note: see the clot of new African American residents in Little Village, by the south branch of the river? that’s the census tract housing the Cook County Jail.)