Summarize the central arguments of and similarities and differences between the three models of ...

The pluralist model sees power as spread among many competing interest groups. Organizations realize some goals, but mostly keep opponents from achieving all of their ends. All people are assumed to have some voice in the political system.
The power-elite model sees power as concentrated among the rich. This model assumes that Canada is not a democracy because the concentration of wealth and power is too great for the average person to be heard. They reject the pluralist idea that various centres of power serve as checks and balances on one another; according to the power-elite model, those at the top face no real opposition.
The Marxist political-economy model explains politics in terms of the operation of a society's economic system. Similar to the power-elite model, it rejects the idea that Canada is a genuine political democracy. However, the Marxist model sees the bias as rooted in the economy and the product of capitalism.