Penn Kemble, who marshaled his skills as a political organizer, theorist and writer to champion a sterner approach by the American government to undemocratic regimes, died Oct. 16 at his home in Washington. He was 64.

The cause was brain cancer, said his friend Joshua Muravchik, a resident scholar at the American Enterprise Institute.

Mr. Kemble's eventful, mostly behind-the-scenes political journey began with socialism, the civil rights movement and opposition to the Vietnam War before it came to center on a fervent anti-Communism that addressed challenges from Central America to Poland. After the demise of the Soviet Union, his pro-democracy focus shifted elsewhere, particularly to the Middle East.

In his most visible jobs, as deputy and acting director of the United States Information Agency in the Clinton administration, he started Civitas, a multinational educational program to promote democracy.

The many organizations he began included one that fought leftward tendencies in churches, another that fought leftists in Central America and still another to steer the Democratic Party to the right after Senator George S. McGovern's pummeling in the 1972 presidential election.

Mr. Kemble was not easy to pigeonhole.

Even as he allied with people like Lt. Col. Oliver North in the Reagan White House to fight leftists in Nicaragua, Mr. Kemble remained a Democrat. To be sure, his kind of Democrat was the hawkish variety epitomized by Senator Henry M. Jackson of Washington and Senator Daniel P. Moynihan of New York, on whose staff he worked. Though his views came to parallel those of the neoconservatives who pushed for the second war with Iraq, he rejected the label.

And though he was described as a "Reagan Democrat," he worried about that president's concessions on arms control. For all his support of the Iraq invasion, he deplored aspects of its execution.

His public visibility, though never great, grew in his later years. In 1999, Secretary of State Madeleine K. Albright appointed him as her representative to a new international organization dedicated to bolstering democracies. In 2002, Secretary of State Colin L. Powell asked him to lead a citizens' group investigating slavery in Sudan. Mr. Kemble devoted his last year to establishing the Transatlantic Democracy Network to bind Europe and North America in promoting democratic institutions, especially in the Middle East. The network's secretariat is at Freedom House, a nonprofit organization that studies and promotes democracy; Mr. Kemble worked there and edited the network's electronic bulletin.

Richard Penn Kemble was born Jan. 21, 1941, in Worcester, Mass., and grew up in Lancaster, Pa. In a 2004 interview with The Lancaster Intelligencer Journal, he said the anti-Americanism he had seen in Europe on a childhood trip had shocked him. He graduated from the University of Colorado, where he founded a young socialists' group but came to disdain the Soviet Union. He moved to New York, where he was arrested in 1964 for taking part in a civil rights demonstration that deliberately blocked traffic on the Triborough Bridge.

His political mentor was Max Schactman, a leftist theoretician who by that time had rejected Trotskyism in favor of the A.F.L.-C.I.O.'s muscular anti-Communist unionism. In 1967, Mr. Kemble formed an organization called Negotiation Now, which called for a negotiated end to the Vietnam War. And in 1969 he began Frontlash, a voter-registration campaign for the A.F.L.-C.I.O.

In 1972, Mr. Kemble was a leader of a group of socialists opposed to the McGovern candidacy. Michael Harrington, a prominent socialist leader, left the group in protest, fuming that Mr. Kemble was "doing the work of Richard Nixon."

Mr. Kemble also helped found Social Democrats, USA, a right-leaning socialist remnant led by the teachers' union chief Albert Shanker.

The Forward, a liberal Jewish American newspaper published in New York, reported in 2003, "The evolution of the Social Democrats is largely a tale of slow half-steps to the right, from socialism to reformist social democracy to cold war liberalism to neoconservatism and finally -- why mince words? -- to plain conservatism."

Mr. Kemble remained a leader of the socialist group until his death.

But he was mainly involved in more conventional politics. He started and led the Coalition for a Democratic Majority in the early 1970's to steer Democrats away from isolationism. In the late 1970's, he worked for Senator Moynihan and for public television as a writer and producer.

In 1986, Mr. Kemble was called one of "Ollie's liberals" for helping win Congressional approval for aid to foes of Nicaragua's leftist government. In 1992, he helped write a foreign policy speech for Gov. Bill Clinton's presidential campaign that urged a more aggressive American posture.