"The effect of prisoner location on population counts may also influence the allocation of political representation and, therefore, political influence (Haberman 2000). In Wisconsin, the number of state prisoners who were housed in other states (known as interstate transfers) caused concern because these prisoners would be counted in the decennial census in the states where they were incarcerated. In 1999, U.S. Representative Mark Green introduced a bill (unsuccessfully) that proposed changes to the census policy so Wisconsin prisoners held in other states would be counted as Wisconsin residents."
Lawrence, Sarah and Jeremy Travis. The New Landscape of Imprisonment: Mapping America's Prison Expansion. Washington, DC: Urban Institute, April 2004.