This week's House Homeland Security Committee hearing on "radical Islam" is needed to highlight and investigate the threat posed by homegrown Muslim terrorists, Chairman Peter T. King (R-N.Y.) said Sunday.

Defending himself against criticism that he is scapegoating a religious community and ignoring threats from other extremists, King said that U.S. Attorney General Eric H. Holder Jr. "is not saying he's staying awake at night because of what's coming from anti-abortion demonstrators or coming from environmental extremists or from Neo-Nazis. It's the radicalization right now in the Muslim community."

King was joined Sunday on CNN's "State of the Union" by Rep. Keith Ellison (D-Minn.), a practicing Muslim who plans to testify at the hearings. Ellison, the first Muslim elected to Congress, said that he agreed with holding the hearings but that the scope was too narrow.

"It's absolutely the right thing to do for the chairman of the Homeland Security Committee to investigate radicalization," Ellison said. "But to say we're going to investigate a religious minority, and a particular one, I think is the wrong course of action to take."

Asked why he would participate in the hearings, Ellison said, "I believe in engaging the process. I think you've got to be involved in the conversation. You've got to offer an alternative view."

King and Ellison had differing takes on the highly charged issue of whether the American Muslim community has helped to counter radicalization. Ellison said, "The stats say 'yes.' " The Muslim community, he said, should not feel frightened but empowered.

King's outlook, however, was not as positive. "I'm aware of a number of cases in New York where the community has not been cooperative," he said, adding that law enforcement officials do not always "get the level of cooperation that they need."

In an effort to set out President Obama's position before the hearings, his deputy national security adviser, Denis McDonough, spoke Sunday evening to the All Dulles Area Muslim Society, one of the nation's largest Islamic congregations.

"The bottom line is this: When it comes to preventing violent extremism and terrorism in the United States, Muslim Americans are not part of the problem, you're part of the solution," McDonough told about 200 people, most of them Muslims.

McDonough recalled Obama's call in Cairo in June 2009 for a "new beginning" with the Islamic world, including with Muslim Americans. McDonough said that "being religious is quintessentially American" and, as Obama has done in the past, celebrated the diversity of the American Muslim community and its contributions to the country.

McDonough said, "Preventing radicalization that leads to violence here in America is part of our larger strategy to decisively defeat al-Qaeda," adding that the government is doing so by engaging Muslim communities on a broad range of issues, not just over security concerns or as intelligence resources.

His speech was interrupted by applause a handful of times, including when he mentioned the recent popular revolt in Egypt, holding it up as evidence that peaceful revolution is more powerful and moral than radical Islamist theory that promotes violence.