After the Republican National Committee raised money with such mailings, congressional Republicans are now conducting a fundraising "census" of their own.
House Minority Leader John Boehner writes in a new mailing that people were specially chosen to receive "the enclosed CENSUS DOCUMENT containing your 2010 Census of America's Republican Leadership."
Like other solicitations in recent months, Boehner's seeks to capitalize on the name of the Census Bureau, which mails official forms to the nation in mid-March.
The Census Bureau is worried the flurry of misleading letters could deter participation, and Democrats are pushing legislation to stop it.
The population count, held every 10 years, is used to distribute House seats as well as more than $400 billion in federal aid. Participation is required by law.
"There are too many reports from too many places to ignore the fact that direct-mail fundraisers are deliberately attempting to confuse people," said Rep. Carolyn Maloney, D-N.Y.
Maloney said the mailings take advantage of awareness generated by the Census Bureau's new multimillion dollar ad campaign that included a spot during the Super Bowl and is now on the airwaves.
Census Bureau spokesman Stephen Buckner said officials are worried about mailings that use the census name. "Any mailings that cause folks to mistakenly believe they are the official census could undermine response rates and increase the costs of the census to follow up," he said.
Three House Democrats this week introduced legislation to require mailings marked "census" to clearly state the name and address of the sender, along with an unambiguous disclaimer that the survey is not affiliated with the federal government.
In the latest solicitation, Boehner asks recipients to help elect a new Republican majority in Congress this fall and stop President Barack Obama's "radical leftist agenda." Among the "survey" questions: "Do you believe the Obama administration and Nancy Pelosi's soft-on-defense, reckless spending, higher taxes and expansive Big Government policies are the right leadership for America?"
Last month, GOP Chairman Michael Steele put out a similar "census" mailing that makes a plea for money along with a form asking voters to identify their political leanings and top issues. It was sent in plain white envelopes marked "Do Not Destroy, Official Document."
Those mailings drew criticism from Democrats, public opinion researchers and a former Republican-appointed census director. But the Postal Service ruled the mailings were legal because they did not use the words "United States Census" or "Census Bureau" and made clear they were paid for by the RNC.
Another "census" mailing by a group called the "Council of Seniors" has been criticized by the Better Business Bureau. The group sent older Idaho residents a "2009 Census of Senior Citizens" and promised the survey results would be sent directly to Obama, Boehner and Pelosi. The council, actually part of the Civil Council, a lobbying group, also asked for donations.
Republican Party groups defended their mailings as appropriate.
"It's clear in the document that this is an NRCC mailer used to collect the opinions of Republicans and, if they're willing, donations to help us retire Nancy Pelosi as Speaker," said Paul Lindsay, a spokesman for the National Republican Congressional Committee, the House GOP campaign arm.
"Unlike the Census Bureau's Super Bowl ad, the response we have received has been positive," Lindsay said in a statement.