Books in the library are organized by call numbers. Below is a list of the first letters of the call numbers that will help you find a variety of books about the topic of Political Science. For a more granular breakdown, see this page from Library of Congress.
J - Political Science
J: General legislative and executive papers
JA: Political science (General)
JC: Political Theory
JF: Political institutions and public administration
JJ: Political institutions and public administration (North America)
JK: Political institutions and public administration (United States)
JL: Political institutions and public administration (Canada, Latin America, etc.)
JN: Political institutions and public administration (Europe)
JQ: Political institutions and public administration (Asia, Africa, Australia, Pacific Area, etc.)
JS: Local government, Municipal government
JV: Colonies and colonization. Emigration and immigration. International migration
JZ: International Relations