Miller-McCune's Emily Badger points out a study on prison-based gerrymandering, a byproduct of how the Census counts inmates. Prison populations are counted as residents of the county where they are imprisoned, rather than where they're from--thus, some rural counties have inflated population counts and subsequently receive inflated representation in state legislatures. And it has an impact:
During the 2000 census, 43,000 New York City residents were counted upstate in this way. Remove them, and seven state senate districts would not have met minimum population requirements and would have had to be redrawn, setting off a chain reaction throughout the state, according to a report released this week by the NAACP Legal Defense Fund.