There is the theory of American government that led to a system which may not be very efficient but is excellent at preventing things we don't want.  As a result, we have a political system that maximizes input into the decision-making process.  But the system is also one that minimizes the potential for policy change. PLease explain:  1) how interest groups make their points of view heard through the political process, and the factors that make them more likely to be successful; 2) the various procedural roadblocks to passing legislation through the Congress; and 3) how the lack of party discipline makes it more difficult for Congress to pass legislation than in a parliamentary democracy.