Well I have a problem with your assumption that the census is accurate to start with. There are many people, not just illegals and others, who refuse to respond to the Census. The Census then takes the information and manipulates it into various counts used by a number of government and social institutions. So if, as you say, the Constitution merely states that all people be counted, don't you think it would be a good thing to know that breakout of citizens vs. non citizens. Don't you think that would be useful information?? The thing is, the illegals will do anything they can to not reveal their status. I had a firiend that signed up to be a census taker in the last census - not realizing that it can be a dangerous job - she was threatened and cursed out and refused. Now if the count is as benign as you seem to think, would that be the case? And i believe the Constitution only calls for a count, and does not specify the questions to be asked.