That power will be garnered legally. But immigrant advocates are concerned about the potential unethical or extralegal power such data can lend to an anti-immigration regime. The Census Bureau drew fire over a decade ago for providing data tables of Arab Americans in each zip code to the Department of Homeland Security. The Census Bureau does collect identifying information like names and addresses of respondents, but is not authorized to share those data. Still, in times of American turmoil the Census Bureau has broken that mandate. In 1943, during the mass incarceration of Japanese American citizens, the Bureau complied with a Treasury Department request for the personal records of some such citizens in violation of the Census Act, according to the historians Margo Anderson at the University of Wisconsin–Milwaukee and William Seltzer at Fordham University in New York City.
Such action today would be illegal. But in the past, not all ICE officials have proven scrupulous about data privacy. In an administration facing multiple data leaks, ongoing foreign infiltration into vital data systems, and a tidal wave of ethics concerns, would any non-citizen reasonably trust their data to remain safe?
The Census question could pose numerous other problems, as well. The data-quality issues resulting from immigrant avoidance of the questionnaire will hurt cities most, since a disproportionate share of non-citizens live in urban areas. The Census is the key mechanism for allocating billions of dollars in federal funding. Any undercounts of non-citizens would siphon money away from cities.
The biggest fallout will likely be political. Punishing liberal-leaning cities would offer Trump a victory in his ongoing culture war, even if it comes at the expense of good and useful data. In a political system where population size dictates everything from the distribution of presidential electors to the boundaries of local voting precincts, undercounts could also undermine the political power of immigrant-rich state like California, and of the urban pockets within the Southwestern desert that threaten to make swing states out of Texas and Arizona. California already announced it will be filing a lawsuit to block the new Census measure. (In a Monday op-ed, published before the latest announcement, the state’s attorney general, Xavier Becerra, and its secretary of state, Alex Padilla, had called on the Commerce Department “reject the Justice Department’s dangerous call to add a citizenship question to the 2020 census.”)
Beyond hurting liberal states, cities, and districts, the other political effects will be in the exact arena in which the DOJ claims it will be using the new citizenship question: redistricting. The courts have held that redistricting and congressional apportionment be done by total population—not by citizen population—and a weaker dataset also weakens that constitutional mandate.