Love them or loath them, political parties - whether as election organisations or as groups within the legislature - are important in a representative democracy. Party funding is one of the major topics of discussion at the moment within the UK - see for example(http://news.bbc.co.uk/1/hi/uk_politics/7122393.stm and its many links. In the United States 'campaign finance reform' is also a controversial issue.
The role of parties within a legislature has long attracted academic interest. Steven S Smith has published a very interesting book this year called "Party Influence in Congress". It's a very useful guide to a number of explanations for party behaviour, and I found it to be a thought provoking read
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