The Department of Homeland Security has stepped back for the past two years from conducting its own intelligence and analysis of home-grown extremism, according to current and former department officials, even though law enforcement and civil rights experts have warned of rising extremist threats.

The department has cut the number of personnel studying domestic terrorism unrelated to Islam, canceled numerous state and local law enforcement briefings, and held up dissemination of nearly a dozen reports on extremist groups, the officials and others said.

The decision to reduce the department’s role was provoked by conservative criticism of an intelligence report on “Rightwing Extremism” issued four months into the Obama administration, the officials said. The report warned that the poor economy and Obama’s election could stir “violent radicalization,” but it was pilloried as an attack on conservative ideologies, including opponents of abortion and immigration.

In the two years since, the officials said, the analytical unit that produced that report has been effectively eviscerated. Much of its work — including a digest of domestic terror incidents and the distribution of definitions for terms such as “white supremacist” and “Christian Identity” — has been blocked.

Multiple current and former law enforcement officials who have regularly viewed DHS analyses said the department had not reported in depth on any domestic extremist groups since 2009.

“Strategic bulletins have been minimal, since that incident,” said Mike Sena, an intelligence official in California who presides over the National Fusion Center Association, a group of 72 federally chartered institutions in which state, local and federal officials share sensitive information. “Having analytical staff, to educate line officers on the extremists, is critical.…This is definitely one area” where more effort is warranted by DHS.

Similar frustration was expressed in interviews with current and former officials at fusion centers in Missouri, Virginia and Tennessee. Daryl Johnson, formerly the senior domestic terrorism analyst at DHS and a principal author of the disputed report, confirmed in an interview that he left in frustration last year after his office was “gutted” in response to complaints.

“Other reports written by DHS about Muslim extremists … got through without any major problems,” Johnson said. “Ours went through endless reviews and edits, and nothing came out.”

The threat of Islamic-related terrorism in the United States has by all accounts captured the most attention and resources at DHS since it was formed in 2002. But a study conducted for the department last October concluded that a majority of the 86 major foiled and executed terrorist plots in the United States from 1999 to 2009 were unrelated to al-Qaeda and allied movements.

“Do not overlook other types of terrorist groups,” the report warned, noting that five purely domestic groups had considered using weapons of mass destruction in that period. Similar warnings have been issued by the two principal non-government groups that track domestic terrorism: the New York-based Anti-Defamation League and the Alabama-based Southern Poverty Law Center.

An annual tally by the latter group of what it calls “Terror From the Right” listed 13 major incidents and arrests last year, nearly double the annual number in previous years; the group also reported the number of hate groups had topped 1,000 in 2010, for the first time in at least two decades.

Citing the complaints that Johnson first made in an SPLC quarterly, the group’s president, J. Richard Cohen, wrote to Homeland Security Secretary Janet Napolitano this week requesting a reassessment of resources devoted to “the threat of non-Islamic domestic terrorism.”

Authorities this year have arrested neo-Nazis who allegedly planted a bomb along the route of a Martin Luther King parade in Spokane, Wash.; arrested six members of an Alaska militia who allegedly plotted to kill state troopers; arrested a Wisconsin man for planning to kill Planned Parenthood workers; and on May 29 arrested a Florida man who claimed to be part of the burgeoning “sovereign citizen movement” after he sprayed a market with AK-47 fire.

A spokesman for DHS, Adam Fetcher, declined to say if the department agrees that the threat of domestically inspired terrorism is increasing or how many analysts are presently assigned to the issue, calling that a sensitive intelligence matter. But he said the evolving risk of group or individual violence is “reflected in our briefings and products over the past year.”

A senior department official provided by Fetcher, who spoke on condition of anonymity to discuss intelligence practices, confirmed that “the number of analysts on a daily basis has decreased somewhat, compared to what it was two years ago.” But the official disputed claims by several current and former DHS officials that only two analysts — including one who is a contract employee — now study the issue full-time.

DHS’s caution or avoidance, as its critics claim, may partly stem from worries that aggressive intelligence operations could be seen as civil liberties violations. A DHS official explained that “unlike international terrorism, there are no designated domestic terrorist groups. Subsequently, all the legal actions of an identified extremist group leading up to an act of violence are constitutionally protected and not reported on by DHS.”

The official added that the FBI — not DHS — is “the primary lead for the federal government” on domestic terrorism. But Johnson, the former DHS analyst, said that if the FBI is the only agency to disseminate detailed reports on domestic extremist groups, “you’ve lost a separate set of eyes that could be looking at this before it develops into a criminal matter.”

When the DHS report on “rightwing extremism” was leaked, Napolitano — who Johnson and other officials say had requested the report and heard a briefing in advance on its conclusions — initially defended it, saying “we must protect the country from terrorism whether foreign or homegrown.”

But after 20 conservative groups sponsored ads calling for Napolitano’s ouster, she said it was disseminated without regular review, and apologized to the American Legion for its warning that veterans could be targeted by militias for recruitment.

The DHS civil rights office subsequently was granted veto rights over all DHS reports on domestic terrorists, Johnson said.

Johnson and others said intelligence reports on the resurgence of militia groups in Michigan and Kentucky are among those being withheld by the agency, which he said was “screening for politically sensitive phrases or topics that might be objectionable to certain groups.”

Multiple briefings for state and local officials on extremist groups such as the sovereign citizens movement — composed of those who reject American legal supremacy — were also blocked, according to internal DHS messages.

David Hawtin, who retired last month as a domestic terrorism analyst at the Tennessee Fusion Center, said “the pendulum has swung to a point where we are missing nodes of connection because there is no obvious crime on the front end.”