That is madness. Common sense must be applied here, w/o an amendment. You can’t be a visitor or an intruder, and count!
I don’t believe visitors are supposed to count; if you are here on a temporary Visa, you are not considered “living here”.
But at this time, there is no way to “not count” people who are actually living in the country, even if they are not here legally.
We could do a sweep and deport them before the census starts. But frankly, Trump has no real interest in deporting most of the illegals; he has targets of interest, but if he could get a wall, he’d probably let most of the settled down ones stay.
ANd if they are living here, they are using resources, and therefore need to be taken into account.
Remember, the 3/5ths compromise was basically saying that a slave, who was not considered a citizen, counted for 3/5ths of a person in the census, both for taxes due from the states, and for apportionment in congress.