It’s as old as the Bible, the taking of a census. The ancient Romans did it. Medieval England did it. It’s written into our Constitution that a census be conducted once every 10 years, and yet, every 10 years, the idea of the government counting the population breeds varying levels of controversy, fear and suspicion.

Which, in a way, is normal; distrust of intrusive government is encoded in the American DNA. “We’ve been doing this 200-odd years,” says census historian Margo Anderson, “and every decade, there is some issue with the census. Because it’s a fairly rare event, when the time gets close, the larger poltical world gets worked up and plays catch-up, trying to figure out why it asks what it asks.”

So the decennial census — the results of which re-apportion legislative representation and determine federal funding — serves as much as a time-lapse snapshot of the country as it does a Rorschach test, revealing what fears, amorphous and concrete, are plaguing the national mind.

In short, they are: Big government, illegal immigration and deportation, religious persecution, same-sex marriage (a first for the census), privacy in the age of the Patriot Act and identity theft, the impact of foreclosure rates on accurate counting, the over-counting or under-counting of certain ethnic groups — the latter an American evergreen.

“People don’t believe the Bureau will hold up the pledge of confidentiality,” says Peter Francese, who, as demographic trends analyst at Ogivly & Mather, relies heavily on census findings. “Mistrust of the government is not a new phenomenon. But the census is money and power. If you have a disgruntled bunch of people who refuse to answer the questionnaire, your state is going to be in trouble. Big time.”

“I said to myself, ‘This is starting to sound familiar,’ ” says Vince Barabba, who served as the director of the Census Bureau from 1973-76 and 1979-80, and remains the only person appointed to that position by Presidents of two different parties. “When I went to the Bureau in 1973, I was the last of the Nixon employees.” He laughs. “There was a considerable amount of concern.”

As there is now, same as it ever was. Two weeks ago, Senators David Vitter (R-La.) and Bob Bennett (R-Utah) introduced an amendment to add a question about legal citizenship to the 2010 Census. This summer, the state of Utah lobbied the Bureau to count Mormon missionaries working overseas, a motion rejected by the Supreme Court. In February, Sen. Judd Gregg (R-N.H.) withdrew his nomination as commerce secretary, sparking concerns that the Obama administration wanted control over the 2010 Census after the White House announced that it wanted the director of the census “to work closely with White House senior management.” Democrats tend to support using mathematical models; Republicans generally prefer a literal head count. Rep. Michele Bachmann (R-Minn.) has said that she will not complete her census form and is encouraging her constituents to do the same. The Latino community — the second most populous in the nation, according the 2000 census — remains divided over whether to “mail back” and be counted, or refuse out of fear the census doubles as a means to root out illegals.

Most unsettling: This summer, a 51-year-old census worker named Bill Sparkman was found hanging from a tree near a cemetery in Kentucky, the word “fed” scrawled on his chest. His death has yet to be ruled a homicide.

“I will be enormously disturbed if it turns out, in any way, that this was connected to him being a census worker,” says Kenneth Prewitt, director of the Census Bureau from 1998-2000. He says that the “noise” surrounding the upcoming census “is unprecedented. There is unusual politicization in DC — Bachmann calling for a boycott, the Vitter bill. Advocacy groups are paying a lot of attention.”

Those who have worked for the US Census Bureau consider it to be one of the most efficient and highly ethical institutions of government. “I’ve always found [the suspicion] interesting,” says former director Barabba. “Here you have an agency that really does something in the best interest of the country.”

Again, that depends who you’re talking to. The seemingly free-floating anxiety about what the government wants to know and why — and whether its numbers are accurate, what they will do with the information collected — is not rooted solely in the lunatic fringe. In 1910, officials in Tacoma, WA., inflated their population count by 20%. “The numbers didn’t add up, and the Bureau did a recount,” says historian Anderson. “There is some concern that there are shenanigans going on to pad the count.”

She also notes that in the 1920s, “Congress never re-apportioned itself, because the rural congressman who held power could not believe the country had tipped urban. They bottled [the results] up for the whole decade. New York really lost there.”

In the 1940s, the Bureau undercounted the amount of blacks living in the country — a determination made when the Selective Service registered more black men than the Bureau counted. (Today, the Bureau uses the same mathematical innovations as public polling.) During World War II, the Department of Defense hired a statistician from the Bureau to identify and locate Japanese-Americans, who were rounded up and thrown in internment camps. Most recently, says Barabba, Homeland Security asked the Bureau for the locations of Arab-Americans, and the Bureau cooperated.

Still, he argues, the average American has no cause for concern. “Let’s say there’s a block where only one Chinese-American lives,” Barabba says. “The Bureau would look at the size of that cell, and if they could draw even an inference that you could ID that one person, they’ll delete that cell and withdraw the information. That, to me, demonstrates the Bureau’s dedication to privacy.” There is also a federal law that prohibits the release of any questionnaire until 72 years after it was submitted.

As for the other controversies and concerns: The Bureau has never asked whether any person is living in this country legally or illegally, and this has only been an issue since 1965, when the borders between the Americas were closed. “We changed the law to make many of the immigrants in the country ‘undocumented,’ ” says census historian Anderson. “But the questions really stay similar from decade to decade.” And the Vitter bill has been introduced far too late to have any substantial impact: “Vitter doesn’t think they’re going to recall the questionnaires,” says former director Prewitt. (Forms have already been printed; to recall and redo them would cost millions of dollars; questions for the 2010 form were submitted to Congress in 2008, during Bush’s term).

“Everybody knows you can’t change the census at the last minute,” adds Barabba. “The question they’re raising about illegals — that’s been part of the discussion since 1980. Every time.” He is against its inclusion in the decennial census: “It’s a census of inhabitants. That’s the law.”

Door-knocks are conducted only on those households that have not mailed back their forms, and Bureau workers are vetted. “We have a lot of quality-control checks,” says Bureau spokesman Stephen Buckner, who adds that the recession has resulted in a swarm of highly-qualified applicants. “We have multiple supervisors. Data is checked for inconsistencies, and if we find them, we rescind the whole workload and send another field operator out.”

Not to be forgotten amidst all the debate: The census is something of a privilege.

“The US was the first civilization to link the census with the government, with how to divide political power,” says historian Anderson. “If you believe in democracy, you believe the people constitute the state. So I would really rather the temperature get lower.”

“It’s the differential undercount that matters,” demographer Francese adds. “If Pennsylvania responds but most of New York doesn’t, it’s a loss of power and money. If people understood that, they’d get over their paranoia and return a complete piece of paper.”