I am in the unenviable position of having to do a crash course in US politics so I can help teach it in a college in England. I am UK citizen and know little about the political traditon in the US.

The topic I need to know more about is the role of political parties and pressure groups. If anyone is able to answer questions from me to this site or knows anywhere else that could help then let me know.

Two party system dominance in the USA and explanations for the
absence of successful third parties.
Recent and contemporary organisation of political parties at federal
and state levels.
The ideologies and traditions of the Republican and Democrat parties
and issues concerning the main differences in their programmes and
policies.
Recent and contemporary internal divisions within the Republican
and Democrat parties and their effects.