The 2020 Census results were legally due by the end of 2020. The Census Bureau choose not to to give them, missing the deadline for the first time since it was put in place in 1976.

The Census will determine the number of seats for each state in the House of Representatives and the number of electors for each state in the Electoral college

The Census Bureau and Democrat lawmakers continually tried to extend deadline past the end of 2020, which the Trump administration rejected so the Census Bureau just didn't release them.

The Census Bureau, despite the Federal law requiring the Commerce Secretary to report to the President the latest state population totals by Dec. 31 2020, failed to do so- keep in mind, they had TEN years to work towards this deadline.. This deliberate delay undermined President Trump's exclusion of illegal immigrants from the numbers, allowing Biden to control the numbers.

The new date the Census Bureau has unilaterally chosen, despite federal law, to deliver appointment counts to the U.S President is now April 30, 2021.

April 1st 2021 is the federal deadline for the Census Bureau to send redistricting counts to the states, used to redraw legislative districts. This has now been unilaterally delayed to no earlier than Sept 30th, 2021.

Coincidentally, after the 2020 election, the Census Bureau has uncovered "millions of flawed records".

Keep in mind, it takes a relatively very small difference in a state population count to have a HUGE impact on how representation in Congress is divided up. After the 2010 count, North Carolina lost a House seat to Minnesota because of a difference of <15,800 people. And in 2000 Utah lost a seat to North Carolina on a difference of only 856 people.

TL:DR Opinion: Democrats have deliberately delayed the Census results past its deadline to "fix" the numbers towards favorable results for Blue states and districts, like they "fixed" the election.