In some ways, Zuhdi Jasser doesn't match the profile of the typical Muslim American. He's an active Republican who has supported the U.S. wars in Afghanistan and Iraq, is an advocate for Israel and says his faith harbors "an insidious supremacism."

Yet the Scottsdale, Ariz., doctor will be the face of American Islam for a Capitol Hill moment. Other than members of Congress, Jasser is the only witness that Rep. Peter T. King (R-N.Y.) has identified so far for his upcoming hearings on radicalization of American Muslims.

King, the chairman of the House Homeland Security Committee, has called the hearings to start March 9.

Although he initially spoke out to promote them, his decision in recent weeks to lie low (he declined to comment for this article) and to keep the witness list and precise questions quiet reflects the complexities of debating the problem, experts say.

Should the hearings focus strictly on hard data about American Muslim cooperation with law enforcement? Should they explore whether U.S. foreign policy helps breed radicalism? Can a congressional hearing in a secular nation explore whether Islam needs a reformation?

That final point is the core tenet for Jasser, a father of three, Navy veteran and former doctor to Congress.

Through his nonprofit group, the American Islamic Forum for Democracy, he debates other Muslims and appears on mostly conservative media to press Muslim leaders to aggressively oppose a "culture of separatism." He wants clerics to disavow scripture that belittles non-Muslims and women and to renounce a role for Islam in government.

As the only non-legislator King has announced he will call, Jasser is drawing a lopsided amount of attention.

King will have a separate panel of congressional witnesses, and he has said he will call Muslim Rep. Keith Ellison (D-Minn.). The Democrats on the committee will call Los Angeles County Sheriff Lee Baca, who has disputed King's contention that Muslims do not cooperate with law enforcement.

With a mostly top-secret list and the first hearing in a few days, anxiety is building among Muslim Americans and national security experts alike. Although some hope that it will improve dialogue, others fear it could set off more prejudice.

National security experts "are holding their breath that it doesn't explode. I've heard that from people on all sides," said Juan C. Zarate, a senior adviser to the Center for Strategic and International Studies who was security adviser to President George W. Bush.

Muslim leaders initially lobbied for King to halt hearings but are now debating whether to try to get on the witness list. Long-standing critics of Muslim American organizations have blasted King for including "apologists" such as Ellison, one of two Muslims elected to Congress.