Check this out:
http://money-law.blogspot.com/2007/02/political-science-rankings.html
Political Science Rankings:
One type of ranking is “Alumni Ranking”
Alumni-based rankings
There are a couple of rankings based on the work of the alumni of a program. McCormick & Rice (1982; 2001) looked at whose graduates publish in five “leading journals” (a journal was leading if it was published by the national or one of the regional political science associations). Michigan, UC Berkeley, Chicago, Rochester and Indiana are the top 5. In a later study, Rice, McCormick & Bergmann (2002) looked at whose graduates publish books that had been reviewed at the flagship journal APSR. Harvard, UC Berkeley, Yale, Chicago and Princeton top that list (when weighed by size of the graduating class, Harvard, Yale, Stanford, Case Western Reserve and UC Berkeley are at the top). Masuoka and Grofman look at which departments have produced the highest number of highly-cited faculty (determined by being in top 400 of all faculty). The top 5 are Harvard, Yale, UC Berkeley, Michigan, and Chicago. They also look at placement records (additional tables and figures) as such – the top 5 in 1991-2000 placements were Harvard, UC Berkeley, Michigan, Princeton, and Chicago.