[0002S]

YES IT'S IN THE CONSTITUTION TO HAVE A CENSUS:

The U.S. Constitution empowers the Congress to carry out the census in "such manner as they shall by Law direct" (Article I, Section 2)

LAW YOU WILL BE VIOLATING (not a constitutional law) IF YOU DO NOT ANSWER:

13 U.S.C. § 221 : US Code - Section 221: Refusal or neglect to answer questions; false answers
Search 13 U.S.C. § 221 : US Code - Section 221: Refusal or neglect to answer questions; false answers

(a) Whoever, being over eighteen years of age, refuses or
willfully neglects, when requested by the Secretary, or by any
other authorized officer or employee of the Department of Commerce
or bureau or agency thereof acting under the instructions of the
Secretary or authorized officer, to answer, to the best of his
knowledge, any of the questions on any schedule submitted to him in
connection with any census or survey provided for by subchapters I,
II, IV, and V of chapter 5 of this title, applying to himself or to
the family to which he belongs or is related, or to the farm or
farms of which he or his family is the occupant, shall be fined not
more than $100.

(b) Whoever, when answering questions described in subsection (a)
of this section, and under the conditions or circumstances
described in such subsection, willfully gives any answer that is
false, shall be fined not more than $500.

(c) Notwithstanding any other provision of this title, no person
shall be compelled to disclose information relative to his
religious beliefs or to membership in a religious body.