That's because, since the first U.S. census in 1790, the federal government has included incarcerated people in the population counts of where they're imprisoned.
In turn, states, which control how voting districts are drawn, and local governments can use those numbers to form districts filled predominantly with people who are locked behind bars and cannot vote in almost all states. Maine and Vermont are the exceptions.
Officials in some prison towns have come up with creative ways to avoid forming voting districts made up primarily of prisoners. But in many others, political lines are drawn around prisons in a way that critics deride as "prison gerrymandering."
記事にもあるけど、選挙区民の3/4が囚人で投票不可の地区のウェブサイト、"input from residents"を尊重、とあるけど、そこの代表が刑務所を訪れたことはないらしい。だとしたら、
"It's almost like your body being used," Alexander said.