From 1950 to 1952 he was a member of the executive committee of the Histadrut. He received an MA in history, economics and sociology from the Hebrew University. After the split in HaKibbutz HaMeuhad he moved to kibbutz Hatzerim. He was one of the founders of Beit Berl where he taught sociology and served as its acting director from 1955 to 1957. From 1964 to 1972 he was chairman of Mapai's public committee for youth movements.
In 1960 he was elected to the fourth Knesset and again to the fifth in 1964, and remained an MK until 1979. He was a member of the Economic Affairs, Education and Culture, Constitution, Law and Justice, Internal Affairs, and the Foreign Affairs & Defense committees. In the ninth Knesset he was chairman of the Education committee. From 1964 to 1972 he was Deputy Minister of Education, and from 1972 to 1974 was secretary general of the Labor Party. From 1974 to 1977 he served as Minister of Education. He set in motion a long school day program in development towns and poverty stricken areas.
After his retirement from the Knesset in 1979 he served in several public roles, including secretary general of the United Kibbutz Movement from 1985 to 1989. He has three sons and eleven grandchildren. One of his sons is high ranking IDF officer, General (res.) Amos Yadlin.