The Trump administration is hellbent on adding a question about citizenship to the 2020 census form. Democrats are passionate about stopping this affront to the Constitution, which calls for an accurate account of everyone living in the country. And they will have a path to do it if they regain the majority in the U.S. House of Representatives on November 6. This is important because a new census question about citizenship or legal status will fuel fears about cooperating with a government survey, and inevitably result in an undercount that will penalize states like California that have a large illegal population.