Members of Congress are responsible for both representation and lawmaking. These two duties are often at odds because what is good for a local district may not be beneficial for the country as a whole. Representation style takes four different forms—policy, allocative, casework, and symbolic—and congresspersons attempt to excel at all four. However, since the legislative process designed by the founders is meant to be very slow, representatives have fewer incentives to concentrate on national lawmaking when reelection interests, and therefore local interests, are more pressing.

The founders created our government with a structure of checks and balances. In addition to checking each other, the House and the Senate may be checked by either the president or the courts. Congress is very powerful but must demonstrate unusual strength and consensus to override presidential vetoes and to amend the Constitution.

Citizens and representatives interact in congressional elections, which in turn are profoundly affected by the way in which state legislatures define congressional districts.The incumbency effect is powerful in American politics because those in office often create legislation that makes it difficult for challengers to succeed.

Representatives want autonomy and choice committee assignments to satisfy constituent concerns. They achieve these goals by joining together into political parties and obeying their leadership and party rules. House and Senate members make their own organizational rules, which means the dominant party in each house has great power over the internal rules of Congress and what laws are made.

The structure of our bicameral legislature and organization of each house can slow the legislative process, yet despite these obstructions, Congress has a wealth of tools and strategies for creating policy. Legislative politics is a complex balance of rules and processes that favors the skilled politician.

Citizens, interest groups, the president, and members of Congress all have a stake in the legislative process. Voters organized into interest groups may have a greater impact on legislative outcomes than may the individual. Yet Congress, with various legislative tools and strategies, holds the most sway over the fate of legislation.