During Wednesday's press briefing, he pointed out the census deadline and Election Day are both less than 100 days away.
"This is a crucial, crucial time for this city and this country," he said. "And we need to do everything we can to make sure everyone is counted, and everyone is heard and everyone votes."
New Yorkers need to complete the census by October 31 in order to be counted.
"Why does the census matter? Because it determines how much federal funding we get, it determines whether we're going to be able to have the kind of mass transit we need, the kind of education for our kids we need – it's very tangible," said de Blasio "Let alone, it determines how much representation new get in Congress."
The mayor went door to door Wednesday evening in South Richmond Hill, Queens, helping collect information for the census as part of a "week of action" to raise awareness.
WATCH: Mayor De Blasio Discusses 2020 Census And Voter Registration
Census Director Julie Menin reported about 51% of residents have self-responded so far.
"COVID is perhaps the starkest reminder about why the census matters. If more New Yorkers would have filled the census out in 2010, we would have had more money today for Medicaid, for our health centers," she said. "In addition, the New York City health department utilizes data in an emergency."
De Blasio also said the city supports the New York City Liberties Union's lawsuit to extend the voter registration deadline.
"This is a constitutional right, people have a right to vote. But there is a problem in this date – a 25 day cutoff before the election. If you haven't registered by that point, you don't get to vote," he said. "That makes no sense in the middle of a pandemic. It means a huge number of people are going to be disenfranchised. We need to make it simpler than ever to vote."
He called the Nov. 3rd election the "most important election in our lifetime."
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