The Census Bureau has severed its ties with ACORN, a community organization that has been hit with Republican accusations of voter registration fraud.

“We do not come to this decision lightly,’’ Census director Robert Groves wrote in a letter to the organization. In splitting with ACORN, Groves sought to tamp down GOP concerns and negative publicity that the partnership would taint the 2010 head count.

“It is clear that ACORN’s affiliation with the 2010 Census promotion has caused sufficient concern in the general public, has indeed become a distraction from our mission, and may even become a discouragement to public cooperation, negatively impacting 2010 Census efforts,’’ Groves wrote.

Stephen Buckner, a census spokesman, confirmed the letter Friday, but declined to comment further. ACORN also had no immediate comment.

In recent months, Republicans have become increasingly critical of the census’ ties with ACORN, the Association of Community Organizations for Reform Now. The group, which advocates for poor people, conducted a massive voter registration effort last year and became a target of conservatives when some employees were accused of submitting false registration forms with names such as “Mickey Mouse.’’

ACORN has said only a handful of employees submitted false registration forms and did so in a bid to boost their pay.

Partly citing ACORN’s role, two Republican senators, Richard Shelby of Alabama and David Vitter of Louisiana, earlier this year blocked a full confirmation vote of Groves for several weeks. Representative Michele Bachmann of Minnesota also has been calling for a census boycott because of her concerns about whether the group would tamper with the high-stakes population count.

Up to now, the Census Bureau had defended ACORN’s involvement, explaining it was one of 80,000 unpaid volunteer groups that the bureau hoped would be able to raise local awareness. But in his letter, Groves said the bureau no longer had confidence that ACORN was effectively managing the partnership.

Lawmakers trying to halt health plan at state level Republicans in more than a dozen states opposed to President Obama’s push for overhauling health care have mounted state-driven efforts to block federal intervention in health care. Republicans in more than a dozen states opposed to President Obama’s push for overhauling health care have mounted state-driven efforts to block federal intervention in health care.

The push-back centers in some areas on fact, such as Obama’s determination that all Americans should be required to get coverage.

But other resistance springs from unfounded notions, such as fears the nation would adopt a single-payer system in which the government would take over health care, something Obama disavowed Wednesday.

“It became very clear that the direction for what they call health care reform at the federal level was putting at risk our health care freedoms, and we need to move quickly to make sure citizens are protected,’’ said Nancy Barto, a Republican state representative and sponsor of a measure in Arizona.

Lawmakers in eight states have filed proposals this year to ask voters to amend state constitutions to prohibit what they bill as restrictions on a person’s freedom to choose a private health care plan, mandatory participation in any given plan, and penalties for declining coverage.

Similar measures were considered in two other states, though they wouldn’t have been decided by voters. And lawmakers in three other states say they plan to file similar ballot proposals in the coming months.

Even if state lawmakers succeed, there are doubts over whether their proposals would take effect if a federal overhaul were passed.

© Copyright 2009 Globe Newspaper Company.