The House of Representatives probe, which today starts to investigate radicalisation in the American-Muslim community, has been accused of being a witch hunt akin to the 1950s anti-Communist campaign.
However, with al-Qaida and its affiliates openly trying to recruit Americans and Muslims inside the US for attacks, King has called congressional hearings “absolutely essential”.
He has also defended his support of Irish republicanism in the 1980s and 1990s.
King, a New York Republican, said the IRA and al-Qaida are very different. He said the IRA was a narrowly focused, home-grown movement while al-Qaida has attacked the United States and other countries.
King maintains he was right to advocate that the IRA be brought into peace negotiations to stop the violence. In 1985 King, then a local politician on Long Island, was one of the most zealous American defenders of the IRA and its campaign to drive the British out of the North.
He argued that IRA violence was an inevitable response to British repression and the organisation had to be understood in the context of a centuries-long struggle for independence.
“The British government is a murder machine,” King said. He described the IRA as a “legitimate force” and compared Sinn Fein leader Gerry Adams to George Washington.
He said: “If civilians are killed in an attack on a military installation, it is certainly regrettable, but I will not morally blame the IRA for it.”
A quarter-century later, King is chairman of the powerful House Homeland Security Committee and has suggested President Barack Obama “use the word terrorism more often” so people understand the seriousness of his purpose.
As King prepares to hold hearings today on what he calls “the extent of the radicalisation” of American Muslims, his past as a defender of armed struggle has led critics to assert he is imposing a double standard.
King has said he believes the Muslim community should do more to renounce al-Qaida and work with law enforcement.
“I am facing reality, my critics are not,” he said. “Al-Qaida is changing its tactics, they realise that it’s very difficult to attack from the outside, they’re recruiting from within.”
King has also accused mosques of being a breeding ground for radicalisation.
Critics say the hearings smack of the effort in the 1950s by Republican Senator Joseph McCarthy, who presided over congressional hearings, to expose and ostracise Communists and their sympathisers in the United States.
Muslim and civil rights advocates have condemned King’s assertions, countering that Muslims in the US are being unfairly targeted and point to tips they have given authorities in the past.
“This hearing does not represent the mainstream view,” said Imam Shamsi Ali, who organised a protest against the probe in New York.
“I don’t see any reason for that perception about Muslims not co-operating,” he said, noting a Muslim vendor alerted authorities to the failed Times Square car bombing in 2010.
That incident, coupled with an alleged bomb plot uncovered last month involving a 20-year-old Saudi student studying in Texas, are among several plots that have boosted concerns by US officials that al-Qaida and its affiliates are determined to strike inside the US any way they can.
Some Muslim leaders have said maintaining the trust of their community is essential to foil plots, and the hearings could jeopardise that as well as feed a view from outside the US that the country is anti-Muslim.
The FBI has also been criticised for sending undercover agents into mosques.
“It could be more damaging at a time there is so much concern about bigotry,” said Sayyid Syeed, national director of the Islamic Society of North America, referring to contentious efforts to block new mosques from being built and a fierce debate over a Florida minister’s threat to burn a Koran.
Set to testify before King’s panel will be the first Muslim American to serve in the House of Representatives, Democratic Representative Keith Ellison.
Republican Representative Frank Wolf, who has seen young Islamists in his district go overseas to fight US forces, will also testify.
The wreckage of the World Trade Centre was still smouldering after the 2001 terrorist attacks when a voice rose above the pain and suspicion to demand that American Muslims not be blamed or mistreated.
“Islam is peace,” declared George W Bush, speaking from a mosque.
As a storm gathers over today’s hearings, it seems of another time to recall that it was President Bush — the bullhorn-wielding avenger who told the world, “You’re either with us or against us” — who told Americans their Muslim neighbours were not only “with us”, they were us.
Nearly 10 years and one president later, suspicions persist.
The nation has not figured out how to accommodate a long-established religious minority while pressing full throttle against homegrown terrorist plots.
“We see no productive outcome in singling out a particular community for examination in what appears to be little more than a political show trial,” 50 liberal groups said in a letter to King.
King asserted that radical Islam is a distinct threat that must be investigated regardless of who is offended.
“You have a violent enemy from overseas which threatens us and which is recruiting people from a community living in our country. That’s... what this hearing’s going to be,” he said.
Obama, son of a Muslim father, has travelled to Turkey, Egypt, and Indonesia, all major Muslim countries, in an effort to heal rifts with the Islamic world. But, amid a surge in the number of domestic jihadist plots discovered, his administration has not come to grips with the divide at home.
While exact numbers are unavailable, authorities say that in the last two years more terrorist plots have been uncovered or foiled than during the last seven years of Bush’s presidency.
Some of that is probably explained by law enforcement improvements over the years — and, notably, by aid to authorities from Muslim community leaders.
Suspicion works both ways.
Muslim leaders accuse FBI agents of spying and serving as “agent provocateurs” in mosques, contributing to radicalism.
Law enforcement officials are nervous, concerned that carefully cultivated relationships with Muslim American leaders could be compromised if the hearings stir a hornet’s nest.
Last night the Republican congressman called Muslims “part of the mosaic” of America. “If there is going to be animosity, I would blame it on my opponents,” he said.