In 2010, the US Bureau of the Census conducted the decennial census of population, as required by the US Constitution. This was the second Census that I worked on. Despite running into people who did not realize that the first such census occurred in 1790, it was a real pleasure to participate in this process. What came after, however, was different.
Once the Bureau published the population numbers (not "personally identifiable"), the politicians in all 50 states got to work redrawing congressional district (and other political unit) boundaries. In Wisconsin, this task was delegated to a private law firm meeting in secret, with the latest in geographic information systems, so they could draw boundaries at the census tract level. This is the lowest level at which census data is available and is the reason that a map of Wisconsin's Assembly and Congressional Districts looks like some of them grew warts.
As it seems, the private firm had some outside assistance. Please refer to the following blog from our Teamster brethren: