President Donald Trump is claiming the 2020 census will be "meaningless" if it doesn't include a citizenship question.

In a tweet Monday, Trump is blaming "Radical Left Democrats" for opposing the "all important" question. The Trump administration moved to add the question to the 2020 census. But it's faced opposition from Democrats who argue it would make immigrants less likely to respond to the constitutionally mandated tally and therefor render it less accurate.

The question has been caught up in litigation in federal courts, where lower courts have ruled the administration's haste to include the question violated federal law and the Constitution.

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Trump tweets that without it, the "Report would be meaningless and a waste of the $Billions (ridiculous) that it costs to put together!"