The Founding Fathers thought the census important enough to mention high up in the Constitution, the fifth paragraph. They commanded an "actual Enumeration," a term that literalists insist means a physical headcount and rules such shortcuts as statistical sampling.

Although the 2010 Census actually started in January with workers going door-to-door in rural Alaska, the real work begins this week with 120 million forms being mailed out.

Filling out and returning the form is no great chore. It has been pared down to only 10 questions - name, address, phone number, age, gender, race and ethnicity, living arrangements and homeownership of the people living at that address.

At times various nefarious theories are floated about why the government wants this information, but it's actually simple and important - money and political power. The government uses per capita figures to apportion the more than $400 billion a year it spends on hospitals, schools, emergency services, roads and other public works.

The Census also determines how many seats in the U.S. House each state will have and the size of the districts they will represent. Fast-growing states like Georgia, Arizona, Florida, Nevada and North Carolina stand to gain a seat. Texas may gain as many as four.

These states are the most prone to undercounts because of their high incidence of illegal immigrants and young adults who, along with low-income individuals, are the least likely to fill out the forms.

The states with the highest participation rates - Iowa, Nebraska and Wisconsin - at around 80 percent, tend to be older, whiter and less mobile.

In 2000, the Census had a national participation rate of 72 percent. The bureau estimates that if everyone mailed back their forms it could save $1.5 billion in call back visits in May and June. To get people to cooperate, the Census has mounted road shows, promotional campaigns, sponsored a car in NASCAR races and spent $2.5 million on Super Bowl ads.

This Census should give us the hard data that has been lacking in the immigration debate. For the first time, the bureau is sending out 13 million bilingual English-Spanish forms and has forms available in Chinese, Korean, Russian and Vietnamese, as well as instructions in 59 languages at the Census Web site, www.2010census.gov.

The Census is periodically the subject of political controversy and this year is no exception.

But it's too late to change the questions being asked this year; and answering them is a civic obligation. Besides, you don't want to let down the Founding Fathers, do you?