WASHINGTON (Reuters) - Congressional Democrats on Monday called on U.S. law enforcement authorities to do more to track and prosecute far-right extremists after a mass shooting at a Pittsburgh synagogue and the mailing of bombs to critics of President Donald Trump.

FILE PHOTO: U.S. House Democrat Jerrold Nadler (D-NY) and Judy Chu (D-CA) hold a news conference to ask the Justice Department to investigate the Trump Foundation's donations to Florida Attorney General Pam Bondi in Washington, U.S., September 14, 2016. REUTERS/Gary Cameron/File Photo

The government must do more to police “hate crimes and domestic terrorism” and prevent gun violence and the spread of white supremacist ideology, said New York Representative Jerrold Nadler and other House of Representatives Democrats in a letter to House Judiciary Committee Chairman Bob Goodlatte.

Calling for an emergency hearing before the committee, Nadler and the other lawmakers wrote that the panel “is charged with confronting the causes of racial and religious violence, assessing the adequacy of federal hate crimes statutes, and protecting the civil liberties of all Americans.” But they did not propose specific new legislation.

“It also falls to our committee to address gun violence in all its forms ... It is our responsibility to respond to this madness, and to do so without delay.”

The FBI said as recently as May that it was pursuing 1,000 investigations into “domestic terrorists.” But some critics have said that federal law enforcement agencies have not done enough.

In the letter, the House Democrats praised the police responses to the incidents, but added that congress should take action to make law enforcement’s work easier.

The absence of a U.S. law specifically outlawing domestic terrorism has made it harder for investigators to track and analyze such crimes, said Josh Zive, outside counsel for the FBI Agents Association. The group, comprised of current and former agents, has been lobbying Congress for two years for such a law.

Current and former government officials said federal agents focus far more on Islamic militants than on right-wing domestic extremists. They said that area is off-limits to the National Counterterrorism Center (NCTC) and the CIA, unless a link to international terrorist groups can be demonstrated.

In June 2017, the Department of Homeland Security (DHS) cut funding for combating U.S.-based extremism and redirected more resources in a $10 million government grant program toward law enforcement efforts focused on fighting Islamic extremism.

A DHS official said its authority to monitor political activities is limited.

Former FBI agent Michael German said federal law authorizes aggressive action against right-wing extremists. “The Justice Department has plenty of authority to treat these crimes as acts of terrorism. It simply chooses not to,” said German, now with the Brennan Center for Justice at New York University Law School.

In Britain by contrast, an authoritative source said the internal security agency MI5 spent the overwhelming proportion of its resources chasing Islamic militants, but now has begun expanding efforts to monitor right-wing extremists.

The U.S. DHS official said the agency collects and reports on domestic extremist movements, but is “prohibited from engaging in intelligence activities for the sole purpose of monitoring activities protected by the First Amendment or the lawful exercise of other rights secured by the Constitution or the laws of the United States.”

In 2009, a report by a team of DHS officials warned of a “resurgence in radicalization and recruitment” on the far right. It said extremist groups were recruiting members using economic hardship, the election of Barack Obama, the first U.S. African-American president, gun control efforts and illegal immigration.

The report was leaked to the media and quickly condemned by conservative activists and politicians. The DHS unit that produced the report later was disbanded, a former senior unit member said, and attempts to re-start some of its activities have gotten little traction.

Mary McCord, who led the Justice Department’s national security division from 2016 until May 2017, said there was a greater need for condemnation of domestic extremism by the “highest levels of government.”

She said federal agents can investigate domestic extremists who threaten violence. But without those threats, domestic groups are seldom investigated as aggressively as foreign groups.

“It’s not a legal question so much as a policy question. There’s no law or constitutional provision that prohibits a lot of the investigative work that could take place,” McCord said.