President Donald Trump on Thursday lashed out at a Supreme Court ruling that effectively blocked his administration from adding a question about citizenship to the 2020 U.S. census , suggesting he could delay the survey.

Seems totally ridiculous that our government, and indeed Country, cannot ask a basic question of Citizenship in a very expensive, detailed and important Census, in this case for 2020. I have asked the lawyers if they can delay the Census, no matter how long, until the.....

.....United States Supreme Court is given additional information from which it can make a final and decisive decision on this very critical matter. Can anyone really believe that as a great Country, we are not able the ask whether or not someone is a Citizen. Only in America!

Kelly Laco, a spokesperson for the Department of Justice, said, “We are disappointed by the Supreme Court’s decision today. The Department of Justice will continue to defend this Administration’s lawful exercises of executive power.”

Trump’s tweets came hours after the Supreme Court, in a surprise move, declined to allow his administration to add a citizenship question to the census. While the Trump administration said it needed the question to better enforce the Voting Rights Act, the court said that rationale seemed “contrived.”

The court ordered the case back to a lower court for further review, which appeared to effectively block the question because the Census Bureau says the forms for the survey need to start being printed on July 1.

A census to count every living person in the United States is mandated by the Constitution to take place once every 10 years. The official date for the 2020 census is April 1, though people can begin to respond in the weeks before that day. Preparations for the census have been underway for years.

Civil rights groups sued the Trump administration over the citizenship question, arguing that it would discourage people of color from participating and effectively give more power to Republicans and non-Hispanic whites. By the Census Bureau’s own analysis, millions of people could be left out. Activists say that because census responses power redistricting, inaccurate information could lead to dramatic electoral consequences.

“If the citizenship question is part of the survey and there is a sizable undercount, states with large immigrant populations could very well lose political representation in Congress,” according to the American Civil Liberties Union. “Depressing census response rates in already underrepresented communities will allow politicians to draw even more skewed legislative districts and further dilute the political power of these communities.”

Activists cheered Thursday’s decision but cautioned that some damage may have already been done.