Here are specific databases that may help. They are included in the Search All box above.
Produced by the US Government Printing Office, GPO includes all types of government documents.
There are over 507,000 documents, covering the years 1976 to present.
A good place to start is in the Library's Reference Room. Political Science books are in the 320 and 900-999 range. Law and Public Administration are in the 340-359 range. Here are a few books among the many available.
American Political Dictionary
REF 920.973 P712a 2002
Constitutional Law Dictionary
REF 342.73 C456c 1985
Dictionary of 20th-century World Politics
REF 909.82 S525d 1993