The Party System in Congress
Congressional caucus
A congressional caucus is a group of members of Congress who collaborate to achieve similar legislative goals. Most members of Congress participate in various caucuses, but all are part of one of the two-party caucuses (unless they are independent and opt to remain separate). The primary party caucuses include the House Republican caucus (also known as the House Republican Conference) for all House Republicans, the Senate Republican caucus (also known as the Senate Republican Conference) for all Senate Republicans, the House Democrat caucus for all House Democrats, and the Senate Democrat caucus for all Senate Democrats. Smaller congressional caucuses function as subgroups of members with a shared interest in advancing common goals, often based on ideology. For instance, in 2021, the House Freedom Caucus comprised approximately 45 conservative Republicans dedicated to limited government, while the Congressional Progressive Caucus consisted of nearly 100 progressive Democrats. Certain congressional caucuses are bipartisan and encompass members from both parties. Examples include the Bipartisan Heroin and Opioid Task Force, and the Climate Solutions Caucuses in both the House and the Senate. The Congressional Black Caucus is officially bipartisan, but only four Republicans have ever joined it. Congressional caucuses may comprise members from both chambers. In 2019, the Congressional Black Caucus had 55 members, including two senators. Smaller caucuses can yield significant influence, sometimes serving as an alternative power to the party leadership. At the beginning of 2018, the House Freedom Caucus opposed Trump’s budget, leading the Republicans to rely on Democratic votes to pass the bill.
Party Leadership
Each party caucus elects a leader, either the majority leader if their party holds the majority in that chamber, or the minority leader if they do not. Majority and minority leaders serve as 'floor leaders' in both chambers, coordinating their party for votes and debates and planning the legislative agenda to promote party unity and achieve legislative goals. The speaker of the House of Representatives, elected by all House members from the majority party, presides over debates, maintains order during sessions, leads the majority party, sets the legislative agenda, and wields significant power, ranking second in presidential succession. If the speaker is from a different party than the executive, they become the primary opposition to the president. The speaker is supported by the House majority leader, who schedules legislation for consideration, as well as other key figures like the assistant speaker, party whip, and caucus chair.
Party Discipline
Party unity has traditionally been lacking, with majority and minority party whips in each chamber coordinating members to vote as instructed by the leadership. However, their ability to maintain party cohesion is restricted. The system of checks and balances prevents party leaders from offering governmental positions to Congress members in return for their backing. In the House, the speaker holds some influence over lawmakers. They determine the composition of the House Rules Committee and appoint chairs and members of select and conference committees. In the Senate, party leaders decide the assignment of senators to various committees, thereby incentivizing compliance with party directives. Often, party leaders must leverage their persuasive skills to rally Congress members behind the party’s objectives, uniting diverse opinions within each party. During 2018-19, Democrats rallied against Trump's border wall to uphold solidarity during the lengthiest government shutdown in history. Resorting to the ultimate measure of ensuring member unity, party leaders may threaten to withdraw party support in future election campaigns or advancement within the party hierarchy. The 2018 midterms signified a shift in Trump's influence over the Republican Party, as numerous critics resigned from Congress and were replaced by more loyal members. Although losing control of the House, Republicans predominantly secured seats where Trump personally campaigned. Only one Republican senator, Mitt Romney, dissented against Trump in the 2019 impeachment trial. Despite the perceived weakness of party discipline, Congress has grown increasingly partisan and divided over the past two decades, with members more inclined to vote along party lines.