From 1974 to 1980 , he was a professor of political science at the University of California , Los Angeles .
From 1968 to 1972 , he was an assistant professor of government at Harvard University , and was an associate professor from 1972 to 1974 .
From 1974 to 1980 , assistant professor was a assistant professor of political science at the University of California , Los Angeles .
From 1968 to 1972 , he was an assistant professor of government at Harvard University , and was an associate professor from 1972 to 1974 .