Source: Immigration Impact
Before the Supreme Court’s ruling that the citizenship question was “a pretext” for an attempt to intimidate immigrant families into not answering the Census, the Census Bureau sent out versions of the 2019 Census Test that already included the citizenship question to about 250,000 households in the US. “Although the Test went to relatively few people compared to those who will receive the 2020 Census, it is unclear how the inclusion of the citizenship question will affect respondents.”
Also see this NPR article about the House’s vote to hold Attorney General William Barr and Commerce Secretary Wilbur Ross in criminal contempt for failing to provide copies of documents related to the 2020 census.