Reading our site here and the right-leaning blogosphere there is a lot of anxiety out there about the 2010 decennial census.
During the 2000 decennial I was an employee of the Census Bureau, I don't put that out as a boast or qualification but rather in the interests of full disclosure, and I'd like to give you my perspective.
The census is required by the Constitution. If fact, if one is a supporter of originalism it is actually one of the few domestic functions of the federal government extant today that is required. It's purpose is to ensure the mathematical integrity of the House of Representatives and prevent the United States from being infested with a system of rotten boroughs and unrepresented cities which was common in England at the time.
Now a strong case can be made that the Census long form is very intrusive. It its defense one can only point out that a) every question asked is required by federal law to be asked, b) everyone in the Census Bureau knows that the long form is too long, and c) we've been on this glide path ever since the Census started asking the names of members of households, their ages, occupations, and places of birth in 1850. One also has to point out that governments at all levels make decisions about schools, hospitals, representation, roads, zoning, land use, etc. based on the federal census. The fact that you don't like some of those programs or uses of census data is really not germane, the question is do you want those programs to operate based on good information or not-so-good information.
Having said that, there is no legal requirement that you be participate. US Marshals are not going to show up and take you away to be waterboarded if you refuse to participate. If you chose not to, eventually a low-paid, temporarily employed, human enumerator will show up at your house to chat with you. If you turn them away they'll ask your neighbors the questions about your household that you refuse to answer. So while you have the choice to not cooperate you really don't have the choice of not being enumerated. It is for that reason that while I am philosophically in tune with the whole declare-your-race-as-American idea (other than the fact that American is a nationality not a race), I think it is doomed to be crushed by the process of physical interviews of households and their neighbors.
Everyone has to use their own prudential judgment in deciding whether or not they will cooperate with the Census. But as you are making that decision you have to decide for yourself how not cooperating moves our cause forward one whit.
There you have it. I confess. I'm a big government squish. I'm a fan of the Census Bureau. I can't imagine how a developed society functions without a regular census (if you use MapQuest or have a GPS device in your car you also need to think about who actually keeps that underlying database of addresses linked to GPS grid coordinates up to date). My family will participate and do so apologetically. Your choice is yours.