Next year we embark on the ultimate national research project: the decennial census. The basic headcount seems as apolitical an endeavor as government could design; everyone, regardless of race, party affiliation or tax bracket, gets tallied just the same.

Yet somehow, the 2010 exercise has become as controversial as the public option.

Republican Rep. Michele Bachmann has declared she won’t fill out most of her census. Republican National Committee chairman Michael Steele has suggested the Obama Administration wants to rig the whole thing. Sen. David Vitter, R-La., has proposed an amendment that would insert a last-minute question requiring people to identify their citizenship status – or lack thereof.

And as one Hispanic organization is promoting widespread participation from that traditionally undercounted population, another group is urging Hispanics to boycott the census all together.

So how did we get to the point of politicizing such a fundamentally nonpolitical — even geeky — data collection (and one that, critics may forget, is carried out every 10 years regardless of which party is in power, by order of the U.S. Constitution)?

“This is not the first time this has happened,” said Jill Wilson, a senior research analyst with the Brookings Institution. “But I do think that this year it’s particularly bad, and there are probably a number of reasons for that.”

A big one is the ongoing debate over immigration reform.

Population counts taken from the census are used to redraw congressional districts and reapportion representation in Washington. Vitter figures high-immigration, Democratic-leaning states like California stand to benefit disproportionately over states like Louisiana from the head count of illegal immigrants who are included in the census but not eligible to vote.

Never mind that it would take hundreds of millions of dollars to alter the questionnaire so late in the process (or that inserting such a personal question should only further offend Michele Bachmann). Most fundamentally, the 14th amendment to the Constitution specifies the census count “the whole number of persons in each State,” language that differs notably from other constitutional references to “citizens.”

Granted, it can be confusing that we apportion representation by counting people who can’t vote.

“And maybe we should at some point have a discussion about whether that’s the way it should be done,” Wilson said. “But the way and timing [Vitter] brought it up is not the way it should be done.”

A report released earlier this year by the Pew Hispanic Center also reveals that illegal immigrants are more geographically dispersed today than ever before, drawing a landscape more nuanced than Vitter’s vision of states with immigrants and those without.

His amendment is unlikely to pass, and Wilson suspects he knows this. But its mere publicity may be enough to discourage immigrants already leery of the census from participating. And each head that isn’t counted represents actual dollars in social services and federal programs communities won’t receive.

Adding up all of the federal programs that rely either in whole or in part on census data to dole out funds, Brookings has estimated that federal spending per head counted was about $1,400 in 2008. The Census Bureau has previously estimated that 10 to 15 percent of unauthorized immigrants were not counted during the 2000 census. If they’re undercounted again at that rate next year, Wilson projects their communities would annually lose between $1.6 and $2.5 billion — money that would be spent on everything from public schools and roads to food stamps and substance-abuse prevention.

Politicians who discourage participation by immigrants jeopardize the federal support needed to accommodate them. Hispanic groups like the National Association of Latino Elected and Appointed Officials get this and are promoting a Spanish-language census campaign around the slogan “It’s time! Make yourself count!”

The National Coalition of Latino Clergy and Christian Leaders has taken the opposite approach, suggesting illegal immigrants refuse to participate in the census to draw attention to needed immigration reform. In a sign this might not be an effective strategy, they seem to have aligned their means, if not their end, with David Vitter (whose own campaign aligns poorly with other Republicans who want help paying for immigrants if no one will stop them from coming).

All of which suggests it makes little sense — or, rather, is just too hard — to politicize the census.

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