Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. EXPLAINER - What's Big Deal About Adding Citizenship Question to US Census? Reuters U.S. President Donald Trump is making a last-ditch push to add a citizenship question to the 2020 U.S. Census, despite a Supreme Court ruling against it last month and criticism by some states and civil liberties groups that the question is meant to deter immigrants from participating and help Republicans gain seats in the U.S. Congress. What is the census used for? The once-per-decade survey is mandated by the U.S. Constitution. Its results have major consequences for states. Census data is used to determine the number of congressional representatives for each state, and dictates how the federal government allocates more than $800 billion in funding for services such as schools and law enforcement. Why did the Trump administration want to add the question? A question about citizenship has not been asked of all households since the 1950 census. It has featured since then on questionnaires sent to a smaller subset of the population. .