Before taking a tour of congressional history, we should review the purposes of the three institutions—committees, political parties, and party leadership—and indicate the conditions that make them more or less powerful decision makers. Then, we will identify a few general propositions about the causes and consequences of institutional development and change.
Congressional Committees as Institutions. As noted in Module 4, standing committees are representative subunits of the whole House or Senate with defined issue jurisdiction. Committees gather and assess information about issues, draft legislation, and oversee government agencies. Committees allow the House and Senate to divide legislative workload into manageable parts and provide the chambers with expertise on issues. Committees are further divided into subcommittees, which cover particular subjects within the committee’s jurisdiction. Committees also allow members to pursue their individual goals: re-election, good public policy, and influence in Congress. Members request committee assignments that align with their goals. The committee chair and subcommittee chairs are the most powerful members of committees; they set the agenda, organize hearings, and preside over committee meetings.
Since committee appointments are made by either party leaders or a party committee, and their recommendations are voted on by the House or Senate, committees are agents of political parties and chamber majorities. Committee power depends on the committee’s standing (temporary or permanent) and the relative degree of discretion, autonomy, and success in gaining approval for the committee’s recommendations.
Political Parties as Institutions. American political parties can be classified in three ways: parties as organizations, parties in the electorate, and parties in government. Party organizations exist at local, state, and national levels and their main job is to help nominate and elect candidates who run under the party label. Parties in the electorate are the voters who identify with the party and vote for the party’s candidates. Parties in government are the elected members to the House and Senate who are responsible for organizing the chamber (including making committee appointments); selecting leaders; and advancing policy that satisfies the party organization and party voters.
American parties are generally considered less “disciplined,” i.e. unified, than parties in parliamentary systems. But party unity, or agreement among the members of a party, has varied over time. Congressional parties are stronger when the party organization has more control over candidate nominations, when voters have stronger attachments to the party, and when elected members agree on policy issues.
Political scientists have conducted a lot of research on trends in party unity and party polarization for the parties in government by gathering data on roll call votes by members of Congress. Political scientists Keith Poole and Howard Rosenthal have been the principal investigators of roll call voting data and they provide data access and some results of their work on Voteview.com. The graph below shows the historical trend in party polarization by measuring the distance between Democrats and Republicans in both houses for each year congress from 1879-2014. The larger the distance the more unified and more polarized are the parties; higher values mark more party polarization and lower values, less polarization.
Party Leadership as an Institution. As we learned in Module 4, the party leadership of the congressional parties consists of several offices. Party leaders are the instruments of the political parties, thus they help to organize the House and Senate (including committee assignments with varying degrees of influence), manage the legislative agenda, build coalitions for or against bills, advance party policy priorities, help candidates get elected, and represent the party in communications with the President and the media. As noted in Module 5, the House has a more formal structure of party leadership than the Senate.
Individual members of Congress generally have a low tolerance for strong party leadership. (Cooper 1977) Members come to the House or Senate with equal standing and place a premium on representing their constituents. Thus, there are limits to strong, centralized leadership in the House. (Jones 1968) Yet the power of party leadership has varied over time. Leaders are strong when they have more formal power to make decisions, when their party is unified, and when individual leaders are willing to take risks to achieve personal and party goals. (Strahan 2007) The first two of these conditions—formal powers and party unity—depend on the members, who are responsible for electing party leaders. “Conditional party government” means that leadership power increases when party unity is high and the two parties are polarized and declines when parties are less unified and less polarized. (Rohde 1991) Leadership power increases when members believe that strong leadership helps them achieve their goals and it declines when leadership detracts from achieving member goals. (Sinclair 1995)