On Wednesday, a battle in Chicago began with an announcement that the legislative boundaries of the 50 wards that comprise the Chicago City Council would be redrawn.The reason: the 2010 federal census reported that 181,000 Blacks have left the Windy City, and 25,000 Latinos, who can be of any race, have arrived.

Chicago’s total Black population declined from more than one million to 887,608 since 2000. The city’s Hispanic population is largely of Mexican descent, while many others are from the Commonwealth of Puerto Rico and elsewhere.

Some Chicago wards may lose African-American aldermen, and Latinos could win a few more.

The Chicago City Council is diverse. Each ward is represented by one alderman or woman, serving a four-year term, who represents 53,000 residents. Currently, according to the Chicago Sun-Times, the last redrawing resulted in 20 Black wards, 13 white wards, 11 Hispanic wards and six wards with a “majority minority” mix of Hispanics, blacks and Asians in six wards. There is one Asian alderman, and two that are openly gay.

In 2010, CapitolFax.com looked at the calculus of Chicago politics, and reported based on data from the Illinois Manufacturers Association that the city’s voters comprised the following percentages: Black: 40.2 percent, white: 35.6 percent, Latino: 13.5 percent, Asian: 3.6 percent and other: 7.1 percent.

The good news for African-American aldermen is that the Black voter turnout is usually “strong,” while CapitolFax.com says the Hispanic turnout  is “notoriously low.”

Scroll down on the above link to see a racial and ethnic map of Chicago.

The political upshot, as Sen. Dick Durbin said in 2010, is that to win city-wide office in the Democratic city, different groups have to work together.  “[Former] Mayor Daley has put together a coalition of mainly white voters and Hispanics, and enough blacks to get a majority. And the liberals would come his way, usually. Not [for] his father, but for him. Now, you put in a black or a Hispanic or a white [candidate], and you say, ‘OK, what’s your coalition?’ You can’t do it alone. No single group can do it,” said Durbin.

In 2010, the Wall Street Journal reported that Chicago’s overall population dropped 6.9% since 2000 to 2,695,598 people. It was the first time since 1920 that the city had fewer than 2.7 million residents.

Ex-Chicagoans were considered to have moved to the outer suburbs, and the South. If patterns from other cities are accurate, the former were probably white, and the latter Black.