:< yeah, I guess that makes the citizenship question pretty much worthless.
No it is not worthless to have the citizenship questions, many illegals will not respond and will actually hide from the census people if they ask questions about citizenship. When those questions were removed from census forms there were tons of ads informing people in Spanish that citizenship questions were not going to be asked and begging them to respond to the census.
It would be far better to deport all the illegals then none would be counted, but that will take time so in the meantime we need to do at least this. Every drop in the bucket counts at this point.