Trump wants the census takers to not count illegal aliens.
Trump orders new census excluding undocumented immigrants
I would not be opposed philosophically, but that is not what the Constitution says.
Art I, Section 2 states: "Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to
the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons."
XIV Amendment states: "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. But
when the right to vote at any election for the choice of electors for President and Vice-President of the United States, Representatives in Congress, the Executive and Judicial officers of a State, or the members of the Legislature thereof,
is denied to any of the male inhabitants of such State, being twenty-one years of age, and
citizens of the United States, or in any way abridged, except for participation in rebellion, or other crime,
the basis of representation therein shall be reduced in the proportion which the number of such male citizens shall bear to the whole number of male citizens twenty-one years of age in such State."
So there are a number of terms here which are not synonymous: inhabitant, citizen, free person.
I do not know what the Founders would have made of ten million illegal aliens being in the country. Would they have changed the verbiage in Art. I to be "citizens" instead of "persons?" Don't know. Anyway, they wrote "persons."
If I was the president, my guidance to census takers would be to determine immigration status (to the extent possible but given the pace of deportations, a lot of illegal aliens will lie about their immigration status), but
count all, because that is what the Constitution directs.