Either on the form or in personal interviews, whether someone is a citizen is indeed asked.
Having worked for the Census and worked in areas obviously filled with illegal immigrants, in personal interviews with such people, I never, ever, ever, ever saw any claim to be citizens. They'd say they were not citizens but immediately add "I have a green card" (whether someone is in the country illegally or not, obviously, is not asked by the Census.)
It wouldn't be remotely realistic for Census workers to actually investigate citizenship status.
We basically agree. I don’t believe previous census counts were as contentious over illegals as this one is likely to become. The mere fact that we are discussing this in ‘07 lends some credence for me.
Congress has the authority to change the rules to exclude illegals and other non-citizens. And you are right, it would likely cause a tremendous political strain as well as a nasty strain on census workers.
The article I posted does a good job of pointing out the pitfalls of changing the census reporting req’s.