President Donald Trump and the Republican Party have spent the better part of the president’s second term radically reshaping the federal government. But in recent weeks, the GOP has set its sights on taking another run at an old target: the US census.
Since the first Trump administration, the right has sought to add a question to the census that captures a respondent’s immigration status and to exclude noncitizens from the tallies that determine how seats in Congress are distributed. In 2019, the Supreme Court struck down an attempt by the first Trump administration to add a citizenship question to the census.
But now, a little-known algorithmic process called “differential privacy,” created to keep census data from being used to identify individual respondents, has become the right’s latest focus. WIRED spoke to six experts about the GOP’s ongoing effort to falsely allege that a system created to protect people’s privacy has made the data from the 2020 census inaccurate.
If successful, the campaign to get rid of differential privacy could not only radically change the kind of data made available, but could put the data of every person living in the US at risk. The campaign could also discourage immigrants from participating in the census entirely.
The Census Bureau regularly publishes anonymized data so that policymakers and researchers can use it. That data is also sensitive: Conducted every 10 years, the census counts every person living in the United States, citizen and noncitizen alike. The data includes detailed information like the race, sex, and age, as well the languages they speak, their home address, economic status, and the number of people living in a house. This data is used for allocating the federal funds that support public services like schools and hospitals, as well as for how a state’s population is divided up and represented in Congress. The more people in a state, the more Congressional representation—and more votes in the Electoral College.
As computers got increasingly sophisticated and data more abundant and accessible, census employees and researchers realized the data published by the Census Bureau could be reverse engineered to identify individual people. According to Title XIII of the US Code, it is illegal for census workers to publish any data that would identify individual people, their homes, or businesses. A a government employee revealing this kind of information could be punished with thousands of dollars in fines or even a possible prison sentence.
For individuals, this could mean, for instance, someone could use census data without differential privacy to identify transgender youth, according to research from the University of Washington.
