When in office Trump intentionally sabotaged the census to try and help Republicans.
The census report is now claiming, no idea if true, there were extreme UNDER counts in several red states and extreme OVER counts in blue states. Trump is big mad, and it's his fault.
If you follow their story the reason for the undercount in red states is undocumented immigrants that live in Texas and Florida, hid from the census because Trump scared them. In the blue states they didn't hide they did as told and responded to the census