Penn Kemble died of brain cancer on Sunday at age 64. He was a hero of American liberalism, even if many American liberals mistook him for something else. In 1972, after George McGovern led the Democratic Party to catastrophe, Kemble, a former activist in the Young People's Socialist League, launched the Coalition for a Democratic Majority, which fought to repudiate the isolationism of McGovern's followers. In the 1980s, he organized Democrats who wanted to oppose communism in Central America more forcefully, and, in the '90s, he helped run the U.S. Information Agency.

Kemble's ideological trajectory paralleled that of many neoconservatives, but he never became one himself, remaining a social democrat to the end. Indeed, while he was already sick, he worked to prepare a conference paying tribute to the legacy of Sidney Hook. His ulterior motive, as all the participants understood, was to revive the social democratic spirit. As news of his illness spread, the event--which drew liberal academics, activists, and leaders--turned into a tribute to Kemble, one he richly deserved.

He was a contributor to these pages during some of their most disputatious days, and he was a kind and smart and important man. We will miss him.