Glotz became director of the Ludwig Maximilians University in 1969 and a member of the Landtag of Bavaria in 1970. He was a member of the German parliament from 1972–1977 and a parliamentary state secretary of the Federal Minister for Education and Research from 1974–1977.
From 1977–1981 Glotz was a senator for science and research in the state of Berlin, and became a member of the parliament again in 1983, resigning in 1996. He was secretary general of the SPD from 1981–1987. Glotz then became director of the University of Erfurt and professor for communication sciences.