It's been said before: that you don't know what the data is used for doesn't make the data meaningless except to you, because you don't choose to find out what the data is used for. If you don't care to find out, then don't. Or educate yourself. Up to you.
I do know there is no legitimate purpose it can be used for and a lot of illegitimate purposes. That's sufficient. What if the census asked if you own a gun, belong to some fringe religion, belonged to a gang, or were a member of the John Birch Society, were a registered democrat/republican, who you voted for ... ? These are completely illegitimate questions. The census was required in the constitution for the purpose of apportioning congressional seats to states. Equal protection means these factors can not be used for any form of discrimination (pro or anti)
I suppose if your mindset is that you are property of the state and they are permitted to treat you like chattel, of if you believe the government always acts in your best interests - then your position makes sense. There is plenty of evidence that is wrong. Ask the Japanese citizens rounded up into interrment camp in WW2
USING CENSUS RECORDS if race is a legitimate question. It is not, it never was, and government claims that the information cannot be abused are tragically wrong.
So what is the "duty of a democracy?"
Majority rules period?
(And yes, I'm well aware of gerrymandering and all the problems of how voting districts are actually created. I'm also not so far up on my high horse that I can't see how minority rights are a fundamental part of a "Western style" democracy and why "race" in the census still matters even if we wish it weren't so.)
How can a form of government have a "duty" ? It's a sort of nonsense use of language. People can have duties and obligations, abstractions cannot. Does a movie have a "duty" does a sandwich have a "duty" ? Gibberish resulting from muddled thinking.
A pure democracy is an aweful thing. It has a well known problem called the tyranny of the majority. The writers of the constitution (unlike you) understood this very well as they had a keen grasp of history. That is why they created a republic form of government not a pure democracy. In this republic there is a constitution which was intended to restrict the powers of the democracy to only certain aspects of control. The enumerated powers of section 1 article 8 is a list of the 18 specific categories where Congress has the power to issue laws. section 9 and the bill of rights list arenas where congress has no power. Other amendments grant and remove various powers to the legislature.
The only reason we can't vote away the rights of minorities is that this is
sometimes prohibited by the constitution. In this way we partially prevent some aspects of a tyranny of the majority.
So you start with some basic misunderstanding of terminology - democracy CAN NEVER protect minority rights. That's an insane thought that we will do whatever some majority wants and minorities will be protected. It is clearly not the democratic aspect of our form of government that protects minority rights. It's the restrictions of the constitution.
The states are COMPLETELY responsible for conducting their elections of congressional representatives (and electoral college representatives too). There must follow the constitutional requirement of not preventing legitimate citizen from voting and treating ALL people (not just minorities) equally.
At one time congressppl were commonly appointed by the state legislature (which has certain advantages and certain disadvantages). Now they are commonly divvied up by geographic congressional district. This has an
advantage for a group that happens to be geographically distributed so that they have a 51% majority in as many districts as possible and a disadvantage for groups who happen to be a 49% minority in as many districts as possible. (it's a bit more complicated that that but ... ) Thus gerrymandering was created to purposely create minorities and majorities by drawing geographic district lines using the numbers of peoples of varying groups as a guide.
Some of the most egregious politically based gerrymandering is *usually* illegal, but all gerrymandering is fundamentally immoral. It can only be used to advantage one group and thus disadvantage another.
If I was emperor for 20 minutes I would mandate that all states must elect their representatives from an "at large" pool of candidates. If some minority group (and I do NOT mean just racial groups) thinks it's important enough to concentrate their votes on specific candidates they can easily do so and have an appropriate sized impact on representation. This is not a perfect solution, but it's vastly superior. It would be better if er elected ALL of congressional representatives from a national at large pool. For example gay ppl erpresent a few percent of the population, perhaps 3%, I don't care to quibble. It that size they's have to all co-locate (an impossible requirement) into a~15 congressional districts to have an appropriate proportional impact on representation. OTOH if they had the opportunity to instead focus their votes in a select group of those standing for the 435 house seats, they could have an immediate and approprite size impact. In realtiy we all belong to numerous minority groups and interests.
So no - I don't think you have even a basic understanding of the issue. Democracy has nothing to do with protecting minorities and never did. That's why we have a republic. GIVING minorities a an advantage by gerrymandering districts where they a have a 51% population advantage means you are necessarily disadvantaging the other 49% of the population - which also belong to other unrecognized minority groups. You allowing government to pick and choose which groups to advantage (or sometimes which to disadvantage) and this is immoral, and should be illegal.
==
Government is an abstraction too, but when we consider our specific federal government as the people who manage it's operation (pres, congress, supreme court); these individuals are required to swear an oath to support he constitution, that is follow the formalism of government process and abide by the limitations on the powers of the federal government. These individuals have responsibilities, duties and obligations to us. They regularly fail at these IMO. The constitution is not well enforced in the recent era and major parts of our federal government exist by use of loopholes that were never intended - the commerce clause for drug interdiction for example. If you'd like a nice example of the Constitution being ignored, then compare your examination by federal officers a at airports with your fourth amendment rights to be secure in your person and papers without a warrant.
Since the constitution is the only protection for minority rights and it is regularly ignored violated, this doesn't bode well for the future of our form of government, and especially for the rights of minorites.