It's the one time when everyone can stand up and be counted. Sometimes, perhaps, twice.
As America readies for the first census of the new millennium, the government is debating the most accurate way to count every American - including, of course, how many telephones and toilets they have.
The question: whether the government should follow the constitutional mandate of a one-at-a-time nose count or use sampling techniques that might provide a more accurate tally.
Sampling has been at the heart of an often acrimonious dispute since the run-up to the last census in 1990. Behind the controversy lie enduring differences between the two major political parties over who might benefit from such a change.
Concerned that sampling could lead to the "discovery" of more voters in hard-to-count urban areas that traditionally tilt Democratic, the GOP-led Congress voted to fund the Census Bureau only until April 15. Republican lawmakers also argue the language of the Constitution is clear, mandating an "actual enumeration" of every American.
Used by pollsters, sampling allows for an educated projection of a population based on counting techniques. One method is counting an area twice and using follow-up interviews to determine who was missed.
Despite the modern twist on the controversy, bickering over the head count is a tradition as old as the Federalist Papers. The seemingly innocuous task of taking a national show of hands has been fraught with controversy since the first effort in 1790, which was widely seen as inaccurate. Even Thomas Jefferson reported being counted twice.
"The current controversy is in a long train of census controversies," explains census historian Margo Anderson, of the University of Wisconsin at Milwaukee.
The traditional squabbling that follows the mammoth undertaking is predictable given the stakes involved. "It all comes down to this. This is where we allocate power and money," says Everett Ehrlich, of the bipartisan US Census Monitoring Board.
Census results dictate how many seats in the House each state gets, as well as how much federal cash flows into areas through block grants and assistance programs. Since the census rewards areas of growth, regions losing representation have often resisted census-based changes.
In 1920, the results showed a massive population flow to urban areas. Republicans, who held the White House and Congress but who represented mostly rural areas, put off reapportionment for most of the decade.
THE census's accuracy has greatly improved in the past century, but by the 1940s, statisticians were aware of the degree of fallibility. When the draft for World War II was instituted, the numbers of soldiers expected to show up were based on estimates from the previous census. Recruiters were surprised when far more men than expected reported for duty. Five percent of white males had been undercounted, and 11 percent of black males had been missed.
The 1960s was marked by an increased effort among minorities to respond to the census and avoid being missed. Nevertheless, the period also marks a heightened effort by cities and states to use the courts to force the Census Bureau to adjust counts.
In the 1990 census, 8.5 million people were estimated to have been missed, and another 4.5 million were double-counted. Although results were worse than the 1980 census - the first time in history the quality of the count decreased - the Bush administration rejected a Census Bureau recommendation to correct the number with sampling methods.
With an estimated 275 million Americans today, the logistics are becoming increasingly difficult. The price tag on the 2000 census is estimated at $4 billion. That number is expected to be at least a billion dollars more if the Supreme Court rejects sampling. "The Constitution says you count everyone. But what if you can't find them?" asks Ms. Anderson.
Republicans and constitutionalists say extrapolating the number of people from areas will in effect amount to making up people that cannot be proven to exist.
Moreover, they argue, there will be less need for it given the redoubled efforts for the 2000 census. "We will have census forms mailed in 30-plus languages, the forms will be available in a variety of places, from 7-Elevens to ... welfare offices. In addition, you can call an 800 number and have one mailed to you," says Matthew Glavin, president of the Southeastern Legal Foundation, which has filed suit against the use of sampling.
"The census is the cornerstone of representative democracy," Mr. Glavin says.