The great numbering

EVERY ten years, says the constitution, America's government must count every person living in the United States. For a country of more than 300m, this is an immense logistical feat: the Census Bureau mailed out or hand-delivered about 134m questionnaires for census day on April 1st. The census is also almost always controversial. Little wonder, given the three ways in which the results help to shape the distribution of political and economic power.

As after every census, the population changes tallied will, first, alter the state-by-state apportionment of seats in the House of Representatives and therefore the electoral college, the body that picks the president after elections. According to the non-profit Population Reference Bureau, the southern and western states will do well; Texas is likely to gain three seats, with Arizona, Florida, Georgia and Utah each gaining one. The losers (one seat each) are likely to be Iowa, Louisiana (thanks to Hurricane Katrina), Massachusetts, Michigan, New Jersey, New York, Ohio and Pennsylvania.

Second, once the census numbers are in, state legislatures will begin early next year to redraw their internal electoral districts, as well as those for the House of Representatives in Washington, DC. Officially, this redrawing is done to reflect population changes; unofficially, the new demographic data are used to gerrymander the districts in such a way as to maximise the ruling party's chances of winning again. A third big consequence of the census is to determine how much loot states bag from the federal government. Andrew Reamer of the Brookings Institution in Washington, DC, estimates that in the 2008 fiscal year alone census data were used to apportion $447 billion of federal assistance (such as Medicaid payments) and $420 billion of federal grants.

The census is the subject of perennial squabbles. Two Republican senators, David Vitter of Louisiana and Bob Bennett of Utah, led an unsuccessful attempt this time to add questions on immigration status to the new form. The Democrats complain that poor people and non-whites are routinely undercounted, a bias which some have proposed to correct by letting the Census Bureau use statistical sampling to adjust the head count. For this census, however, the bureau has tried to avoid that bias by enlisting the tens of thousands of trusted intermediaries—such as churches, charities and firms—to explain the importance of being counted.

Seven former directors, appointed by both Republican and Democratic presidents, have called for the agency to be made more independent. A bipartisan bill being promoted in both chambers would give directors a fixed term of five years, let them report directly to the secretary of commerce, and allow them to testify independently to Congress. But with so much at stake, quarrels over the census are unlikely to vanish.