(CNN) In a controversial move, the Commerce Department announced Monday that the question of citizenship will again be included in the 2020 Census. 
 
 The move comes at the request of the Justice Department, first made in the early days of the administration, saying it was needed to better enforce the Voting Rights Act. 
 
 President Donald Trump's re-election campaign endorsed the idea in an email to supporters last week. 
 
 "The President wants the 2020 United States Census to ask people whether or not they are citizens. In another era, this would be COMMON SENSE... but 19 attorneys general said they will fight the President if he dares to ask people if they are citizens. The President wants to know if you're on his side," the email said. 
 
 Census data is used to determine where federal funds are spent and how congressional districts are drawn, among other uses. The Census is intended to count the entire population, not just US citizens. 
 
 Read More ||||| The size of your child’s kindergarten class. Homeland security funds for your community. Natural disaster preparation. Highway and mass transit resources. Health care and emergency room services. 
 
 Vital services such as these would be jeopardized and our voice in government diminished if the U.S. Census Bureau’s 2020 count resulted in an undercount. Beyond its constitutional role in redistricting, a proper count conducted by the U.S. Census Bureau shapes our everyday lives. If the bureau is ill-prepared for the job or a count is faulty, every state, every neighborhood, faces the risk of losing its fair share of federal funding for its people and its taxpayers. 
 
 Every 10 years, the bureau must count each person in our country — whether citizen or noncitizen — “once, only once, and in the right place.” 
 
 The Trump administration is threatening to derail the integrity of the census by seeking to add a question relating to citizenship to the 2020 census questionnaire. Innocuous at first blush, its effect would be truly insidious. It would discourage noncitizens and their citizen family members from responding to the census, resulting in a less accurate population count. 
 
 Including a citizenship question on the 2020 census is not just a bad idea — it is illegal. 
 
 The Constitution requires the government to conduct an “actual enumeration” of the total population, regardless of citizenship status. And since 1790, the census has counted citizens and noncitizens alike. 
 
 The census has a specific constitutional purpose: to provide an accurate count of all residents, which then allows for proper allotment of congressional representatives to the states. The Census Bureau has a long history of working to ensure the most accurate count of the U.S. population in a nonpartisan manner, based on scientific principles. 
 
 Since the last census in 2010, the public servants at the Census Bureau have been planning and fine-tuning the 2020 census. This work includes painstaking determinations of which questions to ask on the census and how to ask them. 
 
 In December, the U.S. Department of Justice formally asked the bureau to include a question on citizenship in the 2020 census. By March 31, Commerce Secretary Wilbur Ross must decide whether to add this question. 
 
 This request is an extraordinary attempt by the Trump administration to hijack the 2020 census for political purposes. Since the first day of his presidential campaign and through his first year in office, President Trump has targeted immigrants: vilifying them and attempting to exclude them from the country. Think travel bans, repeal of Deferred Action for Childhood Arrivals, ramped up Immigration and Customs Enforcement raids that tear parents away from their children. Immigrants and their loved ones understandably are, and will be, concerned about how data collected in the 2020 Census will be used. 
 
 California, with its large immigrant communities, would be disproportionately harmed by depressed participation in the 2020 census. An undercount would threaten at least one of California’s seats in the House of Representatives (and, by extension, an elector in the electoral college.) It would deprive California and its cities and counties of their fair share of billions of dollars in federal funds. 
 
 These concerns are real and they are bipartisan. The past four census directors, who served under both Republican and Democratic presidents, have all publicly voiced opposition to a citizenship question based on the certain consequence of an undercount. These concerns affect red states and blue states alike. 
 
 The politicization of the 2020 census must stop now. By the end of the week, the bureau will announce its final list of census questions. Secretary Ross should uphold the government’s constitutional duty to count all people in every part of the country — and reject the Justice Department’s dangerous call to add a citizenship question to the 2020 census. ||||| Breaking News Emails Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings. 
 
 March 27, 2018, 2:45 AM GMT / Updated March 27, 2018, 4:02 AM GMT By Associated Press and Richie Duchon 
 
 WASHINGTON — The Commerce Department said Monday that the 2020 U.S. Census would include a question about citizenship status. 
 
 The Commerce Department said in a statement that the citizenship data would help the Justice Department enforce the Voting Rights Act, which protects minority voting rights. 
 
 Opponents have said the question will discourage immigrants from responding to the census. A coalition of state attorneys general urged the Commerce Department last month not to add such a question, saying it could lower participation among immigrants and cause a population undercount. 
 
 The decennial census helps determine political representation in Congress, federal funding of programs and other matters. 
 
 The Commerce Department said that from 1820 to 1950, almost every decennial census asked a question on citizenship in some form. 
 
 California Attorney General Xavier Becerra said in a tweet that he would sue to challenge the legality of the move. "Including the question is not just a bad idea — it is illegal," Becerra said. 
 
 In an op-ed in the San Francisco Chronicle, Becerra and California Secretary of State Alex Padilla said the decision seems "innocuous at first blush" but would dissuade non-citizens living in the United States from participating and would result in an inaccurate population count. 
 
 The officials argued that an undercount of the population would disproportionately affect states with high immigrant populations, like California, depriving them of adequate money for public safety, health, transit and other resources. 
 
 "This request is an extraordinary attempt by the Trump administration to hijack the 2020 census for political purposes," Becerra and Padilla wrote in their op-ed.
– Advocates say the change is simple common sense—but critics say it doesn't make a lot of sense to hold a census that won't accurately count the population. The Commerce Department has confirmed that the 2020 census will include a question about citizenship, a move that opponents warn will cause undocumented immigrants not to fill in the form, leading to a major undercount in states including Texas and California, NBC reports. The Commerce Department says the question is nothing new, noting that there was a question about citizenship on every decennial census from 1820 to 1950. The census—which is meant to count the entire population, citizens or not—is used to determine federal funding levels and representation in Congress, among other things. "The President wants the 2020 United States Census to ask people whether or not they are citizens," the Trump campaign said in email to supporters last week, per CNN. "In another era, this would be COMMON SENSE... but 19 attorneys general said they will fight the President if he dares to ask people if they are citizens." The attorneys general in opposition include California's Xavier Becerra. In an op-ed at the San Francisco Chronicle, he writes that the move "would discourage noncitizens and their citizen family members from responding to the census, resulting in a less accurate population count." This would not only reduce funding for public services, it would violate the Constitution's requirement for an "actual enumeration" of the population, he writes.