(Map: Prison Policy Initiative, 2011)

This map originally appeared in Testimony of Peter Wagner Before the Special Joint Committee on Redistricting of the Massachusetts General Court on May 31, 2011.

In this example from the last round of redistricting, the 12th Hampden district in Springfield and Wilbraham was drawn to contain 41,642 just below the then-maximum of 41,666. But as this district includes Springfield which has one of the highest rates of incarceration in the state, a large number of people in prison are residents of this district, and the actual population was likely out of the permissible range.