What legitimate use is that? The use is to help the government run un-constitutional programs, and to provide free data that corporate america would otherwise have to pay to obtain itself. The only legitimate info that the Census should ask is how many people live in your house. That's it.
You nuckle dragging Neanderthals are really funny. Too bad you give real conservatism a bad name. Get it through your head there probably never was this grand period you think of when government only did was was enumerated. In fact there is a good chance that you live in a part of the US purchased unconstitutionally by Jefferson. We are never going back to pre-war (I mean pre-Civil War) government so get used to the real world. Or at least dont embarrass yourself.
"What legitimate use is that? "
Ever take an economics course? If you have you will know that predicting future econmic trends is best served by reviewing past data. Unless you think the government plays no role in the US economy you can probably figure out why the government has a legitimate need for data.