Minnesota groups preparing for the 2020 census expressed alarm Tuesday over the Trump administration's decision to include a question about citizenship, fearing fewer immigrants will participate in the crucial survey.

Commerce Secretary Wilbur Ross announced the change on Monday night, after the Department of Justice requested a citizenship question to aid with enforcement of the Voting Rights Act. Within hours, the state of California's attorney general filed suit claiming the change is unconstitutional, and local groups were warning about a flawed count.

The stakes are particularly high for Minnesota in 2020, as the state is among those poised to lose a congressional seat for the first time in half a century due to faster growth elsewhere in the country.

"It's one more action, along with the issues around underfunding and delayed funding, that moves us down the path of having a failed census," said Bob Tracy of the Minnesota Council on Foundations, which has led early organizing efforts for the census.

The census is conducted every 10 years, and its findings about the country's population determine where federal money is spent, how political districts are drawn and many other critical decisions. The 2010 census included 10 questions, mostly regarding the gender, age and race of people living in each household.

The census also included a question about citizenship until 1950, when it was folded into surveys given to just a sampling of the population. Based on that smaller data set, the American Community Survey, it is estimated that about 223,000 people living in Minnesota are noncitizens.

The Justice Department says the citizenship question should be restored to the census so it has the data to prevent states and local governments from diluting the voting power of certain racial groups through redistricting.

The department can only do that by analyzing the population of voting age citizens, it wrote in a letter this December, arguing that the ACS lacks the precision needed for that task. The letter noted that 2010 was the first time it had to rely on that data for redistricting, since it replaced a "long form" census previously issued every 10 years.

Ross emphasized in a letter detailing the change that he examined concerns about depressed response rates, but said the U.S. Census Bureau could not prove this would be the case.

"I find that the need for accurate citizenship data and the limited burden that the reinstatement of the citizenship question would impose outweigh fears about a potentially lower response rate," Ross wrote.

DFLers U.S. Sen. Tina Smith and U.S. Rep. Betty McCollum have co-sponsored bills in Congress that would prohibit a citizenship question on the census. The legislation currently has no Republican cosponsors.

"The census touches the lives of each and every person in Minnesota, but in order for it to be accurate, it must be absent of political interference," Smith said in a statement. "Asking census respondents their citizenship status is a reckless stunt that is designed to intimidate our immigrant communities and that will ultimately harm the response rate and undermine the accuracy of our 2020 census."

'Strikes that nerve'

Federal law requires that information provided to the census remain confidential within the agency, ensuring it is not used against those providing it. But advocates expressing concern Tuesday said they are worried the citizenship question will scare people away. Minnesota had the second-highest participation rate in the 2010 census, after Wisconsin.

Immigrant communities were already wary of identifying themselves on the census before the question was added, said Rodolfo Guttierez, who is on sabbatical as executive director of the St. Paul-based nonprofit Hispanic Advocacy and Community Empowerment through Research.

"Especially among refugees and undocumented communities of immigrants, they might be even more reluctant to come up front and say, 'Hey, I am Salvadoran, I am Guatemalan, I am Mexican.' Whatever they are," Guttierez said. "So we are going to have a very severe undercounting of population in Minnesota."

State Demographer Susan Brower has already been traveling around the state preparing communities to begin organizing for the count, which is often dubbed the country's largest peacetime mobilization. She said there are fears about trusting government, which have been amplified during the heightened immigration debate of the Trump administration.

"Even people who are here legally have heightened concerns that inadvertently they'll do something wrong — that they'll step over some boundary they didn't know was there," Brower said. "So I think that this narrative around immigration is really ramped up right now. And putting the citizenship question just strikes that nerve that's already raw."

Not everyone is convinced about the chilling effect of the Trump presidency on census response, however. Steven Camarota, director of research at the Washington, D.C.-based Center for Immigration Studies, which advocates for tougher immigration regulations, studied ACS refusal rates and found they were climbing long before Trump's rise.

" You would have expected it to really have jumped in 2015 — but especially in 2016," Camarota said. "Didn't happen."