I can understand the sentiment, but I fail to see how such a proposal could pass consitutional muster.
The clause in question does not speak about citizens - it refers to “free persons”, indentured persons, indians and all others (i.e. the non-free, slaves). Non-citizens (legal or not) are not slaves and not indians - so representation must consider them.
So the solution is to flush out the wetbacks,put them on a bus,build a wall worthy of the East Germans (but with a *much* different purpose) and pass laws providing for serious jail time and fines for anyone employing a wetback and for any person violating our citizenship/residency laws.
The issue has two parts: 1) what questions are asked in the census (I think Congress has the legitimate authority to legislate this).
2) use citizen count only to determine redistricting (would require a Constitutional Amendment per stated amendment process).