[indthkr]

"Will such information, once gathered be used to apportion electoral votes as the census does"

One answer to your question is another question: if Trump can't get a citizenship question on the census, can the 2020 Census be invalidated by showing with other government data that it doesn't accurately capture population results?

[Brian Griffin]

“Section 1. All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States...

“Section 2. Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed.”

In theory, Amendment XIV might require perfect accuracy, which is impractical.