A request by the Justice Department to add a citizenship question to the 2020 Census could shift the nation’s balance of political power from cities to more rural communities over the next decade and give Republicans a new advantage drawing electoral boundaries.
Population numbers produced by the census are used in many ways, notably to draw political districts and distribute government funds across the country. Adding questions to the decennial survey is usually a controversial and difficult process because of the potential to affect both of those functions — either by suppressing census participation or by creating new ways to define populations...
...A switch to using eligible voters would effectively eliminate millions of people from the Texas population for the purposes of redistricting, leading to less urban districts and more rural ones, shifting the balance of power away from heavily Hispanic areas, and likely more heavily Democratic areas, where more noncitizens and children live.
Beveridge explains the direct impact this would have on political representation:
“All of the districts with noncitizens in them and all of the districts with kids in them would have less representation,” said Andrew Beveridge, a demographer at Queens College in New York, who called the idea the “holy grail” for Republicans seeking to maintain a partisan advantage.
The article also cites Social Explorer Webby Award-winning visualization project of the Supreme Court case Evenwel v. Abbott, which could have changed redistricting by counting eligible voters only instead of all residents.
Using census data, Beveridge ran an experiment in 2016 to roughly estimate the partisan effects of switching to eligible voters and concluded that Texas Republicans would pick up about seven state House seats and one state Senate seat. If the same system were adopted in Florida, California or New York, Republicans were also likely to pick up seats, he found.