Labor Zionist leader, intellectual, and writer. He was the acknowledged intellectual leader of Labor Zionism in America, serving as editor of its weekly, Der Yiddisher Kempfer, and the English monthly, the Jewish Frontier. During World War II, he was chairman of the Executive Council, and during the UN deliberations in 1947 on the establishment of Israel he helped win over many of the Latin American delegates to the Jewish cause. At his death, he was mourned as a leader of great spiritual force.