The structure of Congress, both as it was designed by the founders and as it has evolved over the past two centuries, heightens the tension between pluralism and majoritarianism in American politics. Under the Constitution, the system of checks and balances divides complete lawmaking power between Congress and the president. In addition, members of Congress are elected from particular states or congressional districts and ultimately depend upon their constituents to re-elect them. Two facts suggest majoritarian influence on Congress. First, to become law, legislation must be passed by a majority vote in each house. Second, in recent years at least, the party system, which may act as a majoritarian influence on politics, has had a greater impact on the way members actually vote. Considering the thin Republican majority in the House and the evenly split Senate resulting from the election of 2000, Congress will likely be more pluralistic in order to pass legislation on key issues faced by the nation.
Much about the structure of Congress reinforces pluralism. The committee structure encourages members of Congress to gain expertise in narrow policy areas. The experience members gain in these areas often leads them to look after particular constituencies or special interests. Furthermore, since the outcome of the legislative process is usually the result of vote trading, logrolling, bargaining, and coalition building, any final product is likely to represent all sorts of concessions to various interests.