In Congress the factions decide

Caucuses, caucuses everywhere. Source: Rep. Ritchie Torres, X.com.

House Republicans are battling over what should be included Donald Trump’s “one, big, beautiful bill.” Among the concerns from GOP lawmakers: Medicaid cuts, an increase in the SALT tax deduction cap, and “deficit hawks” who assert that any proposed tax cuts must be balanced out by concurrent spending cuts.

Such infighting among a party should be no surprise. Intraparty disagreement (or party infighting) between party leaders and their rank-and-file members is a longstanding feature of Congress. The conventional wisdom we have held for decades about cohesive parties – ones largely in agreement with each other on the issues – too often is overstated. The parties may come together to vote on final pieces of legislation (measured by the widely-used roll call votes) – but this leaves out all important consideration of the intraparty negotiations that need to happen first to keep fellow partisans supportive of any legislation.

Individual members of Congress do not want to go at a problem alone. There is strength in numbers, so legislators turn to forming organizations in the House known as caucuses, or, more officially, Congressional Member Organizations (or CMOs). These caucuses, as the late political scientist Susan Webb Hammond wrote in 1985, can be classified into several groups depending on their overall purpose. And Hammond’s observation from four decades ago – that the number of congressional caucuses had seen a rapid increase – still holds true today. In the 118^th Congress (2023-25), the Committee on House Administration recognized hundreds of caucuses in the House alone. There are then some caucuses, such as the House Freedom Caucus, who are not officially recognized but still can exert tremendous bargaining power over the legislative process – and who can even give the party a headache by blocking aspirants to the Speakership and voting down rules issued by the Rules Committee.

Party leaders realize that they need all their fellow partisans on board in order to advance a piece of legislation. Further, these caucuses have had no issue in threatening to withhold their support from legislation. And this is certainly not an issue that has just bubbled up suddenly. Consider the lengthy party infighting surrounding both the Bipartisan Infrastructure Law and the Inflation Reduction Act during the 117^th Congress (2021-23). University of Chicago political scientist Ruth Bloch Rubin wrote about the influence of the moderate Blue Dog Caucus in negotiating the Affordable Care Act during Obama’s first term – as well as the House Freedom Caucus’ threat to sink their party’s plan to repeal-and-replace the Affordable Care Act.

And these caucuses today are further aided by the remarkably narrow size of their congressional majorities, which makes it all the more important for party leaders to negotiate agreements between the factions of their party. In the House, Republicans claim 220 seats, just two seats over the necessary 218 for a party to claim a bare majority. In the Senate, the GOP holds 53 seats – slightly more than the 50 needed to constitute a majority in that chamber – but still leaving little wiggle room for leaders to maneuver.

It’s safe to say that GOP leaders – in particular, House Speaker Mike Johnson (R-LA) and Senate Majority Leader John Thune (R-SD) – will have their work cut out for them when constructing any substantive bill that fits all their members’ needs. For any bill to advance, Johnson can only afford two defections in the House, while Thune can only afford three Senate defections (assuming he can garner the vote of Vice President J.D. Vance to break any ties). And Thune will only be able to enjoy a 50-seat winning coalition if the bill is passed through a process known as budget reconciliation, which only requires a bare majority of Senators to advance the legislation. On top of that, the ultimate fate of what can be included in reconciliation bills rests with the Senate parliamentarian, who has in the past struck down party priorities from being eligible to be included in these bills.

More than ever, party leaders face an increasingly difficult challenge in keeping their parties unified, further complicated by increased bargaining power, both from individual members and party caucuses, and narrow majorities in both chambers. Of course, leaders only care about creating the most minimal winning coalition to advance legislation. But in today’s modern Congress, it is intraparty factions who will make their demands loud and clear. And party leaders will have no choice – if they want to claim a legislative victory – than to listen.  

John C. Paschold is a Ph. D candidate in political science at Vanderbilt University, where he is a Russell G. Hamilton Scholar. He has broad research interests in the field of American politics, including American political institutions, American political behavior, and quantitative methods.