Many primary resources for politics are freely available online as well as in print. Below are some examples of resources available from national and international government bodies.
The United Kingdom
There is no single collection of political party manifestos in Cambridge, but there are several scattered throughout the different libraries. For specific manifestos, search the name of the party and year of publication along with a keyword (like 'manifesto') in iDiscover. The manifestos of the three major political parties have been collected in books which are held in the University Library and elewhere:
The Conservative Party general election manifestos, 1900-1997
Labour Party general election manifestos 1900-1997
Liberal Party general election manifestos 1900-1997
American Platforms (party and presidential)
The United Kingdom
Census data can be found on both the Vision of Britain site and the UK Data Service
The United Kingdom (Hansard)
America (Congressional Record)
Australia (Hansard)
Canada (Present and Historical)
Ireland (Dáil Debates)
New Zealand (Hansard)
United Nations (General Assembley)