4 questions about Trump’s proposal for a new census

President Donald Trump wants the Commerce Department to conduct a new census that excludes undocumented immigrants.

“I have instructed our Department of Commerce to immediately begin work on a new and highly accurate CENSUS based on modern day facts and figures, and, importantly, using the results and information gained from the Presidential Election of 2024. People who are in our Country illegally WILL NOT BE COUNTED IN THE CENSUS,” Trump wrote in a Truth Social post on Thursday.

READ MORE: Trump wants to change how the Census Bureau collects data

The Constitution requires the United States government to conduct a census every decade. The data collected on populations across the country are used to determine how many representatives each state should have in Congress, in accordance with the 14th Amendment. Census data have also been used to help lawmakers better understand the needs of the communities they were elected to serve.

Trump’s directive is the latest move from his administration to remove or alter federal data that do not align with the president’s political agenda. On Aug. 1, he fired Bureau of Labor Statistics commissioner Erika McEntarfer after her office issued a jobs report that showed rising unemployment during Trump’s push for more tariffs.

Days after Trump’s inauguration, many datasets linked to public health, climate change, immigration and criminal justice and human rights were deleted from government websites. A few datasets reappeared, but variables were either taken down or recoded to erase racial, ethnic or gender diversity. Data archivists, researchers and others have worked to recover and save some of these datasets.

At its core, the act of removing federal data boils down to who the government chooses to recognize and who it does not, multiple experts have told PBS News.

WATCH: Firing of labor statistics head undermines trust in key data, ex-Trump official warns

“We need to make sure that there is independence and integrity in the measures that we produce,” said Amy O’Hara, a research professor at Georgetown University’s Massive Data Institute and president of the Association of Public Data Users.

A former senior executive with the Census Bureau, O’Hara has tracked the handling of federal data for years, including during the current administration. PBS News asked her about Trump’s plan for a new census and what it could mean. This interview has been lightly edited for clarity.

Does Trump have the power to do this?

AMY O’HARA: The census gets its marching orders from the Congress. And so the president may make requests, but those need to be taken up by the Congress and then have funding go to the Department of Commerce that then goes to the Bureau of the Census.

The census usually considers a design plan for its upcoming data collections, and then they get funding and then they pursue that. They do testing and research and planning so that they can collect accurate statistics. Things are seldom done on the spur of the moment.

Why are undocumented people counted in the census?

AMY O’HARA: The census has been counting everybody resident in the United States. That’s the way that this has been done for decades.

Because whether somebody is just visiting the country or in various stages of legal status, they consume services. And we want to make sure that we are ready to have the right defenses, the right services – things like bridges and roads, schools and hospitals. And so it’s important to understand everybody that’s in the country.

Why is Trump doing this?

AMY O’HARA: I cannot guess as to the actual motivations. There is a law in the books right now to have a mid-decade census. But there’s never been funding to do it.

And it’s also interesting to note that, if we did a mid-decade census, those results could not be used for apportionment purposes. That’s actually in that same law, in Public Law 94.

What are the implications for local communities?

AMY O’HARA: One of the things that I’m most worried about is if the Department of Commerce does direct the Bureau to undertake this quick new enumeration activity, unless there are additional funds put in place and hiring allowed, it is going to displace effort on other work that the Bureau was doing. That could be producing the surveys, the planning for the 2030 census, planning the economic census, the regular, timely, accurate production of economic indicators.

Something that is a big new initiative, it would need to be resourced adequately.

I was actually excited to read the president’s initial comment because we want to invest in having an accurate census. Yes, so do I. That’s great. Let’s make sure that we’re resourcing 2030.

If you want to do a mid-decade census, let’s resource that, too. I am all for a full and complete and accurate census. It just has to have the same values and principles of making sure that we’re using it only for statistical purposes and that it is truly full and complete.