American politics concerns the study of American institutions and political behavior. At Columbia and elsewhere, American politics is one of the largest subfields in terms of faculty and students, and the field has been responsible for generating many methodological innovations in the discipline.

The department engages in the full range of topics in the study of institutions, including in areas often neglected even in top departments: bureaucracy and the oversight of regulatory agencies, state politics, courts, and electoral rules and in particular primaries. In the area of political behavior research, the department also engages a broad range of topics, including the politics of race and ethnicity, voting, political psychology, and connections between public opinion and policy. A number of Columbia scholars pursue both the institutional and behavioral lines of work, and they have contributed substantially as well to the historical study of American political development from both institutional and behavioral perspectives.

American politics scholars are also among the discipline's leaders in the design of field experiments and the study of elections.

Comparative politics is often thought of as the study of politics outside the United States. This definition is becoming less relevant in a globalized world, and there are many intellectual exchanges between the subfields of American and comparative politics. The line between comparative politics and international relations is also increasingly blurred.

With its broad geographic scope, comparative politics covers a diverse range of research questions: Why are some countries, but not others, democratic? What accounts for variation in welfare policies across countries and over time? How do political institutions shape economic development? Under what conditions do ethnic relations become politically relevant? These are all questions of common concern in comparative politics, and scholars use a range of methods from field experiments to ethnography to statistics to study them.

Many scholars in comparative politics, including in Columbia's department, have deep substantive knowledge of particular regions and also address questions of general interest in the field of political science. The Columbia comparative politics group is especially well known for work in comparative political economy, economic development, and democratization. The group also studies the politics of Africa, East Asia, Eurasia, Europe, Latin America, and the Middle East.

The Columbia comparative politics group is known for its methodological diversity and ranks among the best in the country.

International relations is traditionally divided into two main fields: international security (the study of war, conflict, peace, etc.,) and international political economy (trade, foreign direct investment, international finance, etc.). However, it increasingly includes other areas of global concern, including the environment, human rights, and international law, as well as fields that span substantive areas, such as the study of international organization.

Columbia has been known for a long time as one of the very top places to study international security. The international relations group cooperates with comparative politics colleagues in mounting one of the strongest programs in the study of civil wars.

Faculty in the department use a wide range of theories and a variety of methods, from formal models to statistical analyses, to case studies and archival research. They urge students to deploy multiple methods and to deal with alternative explanations. Most of the group's graduate students publish revised versions of their dissertations either as a book or as a series of articles.

Political economic theory spans the subfields of American politics, comparative politics, and international relations, and therefore complements students' interests in those fields.

Political economic theorists work with formal models of political institutions and behavior. The group's faculty have developed influential theories of elections, conflict, legislatures, and bureaucratic politics. These theories are useful for motivating empirical work, and increasingly they form the basis of experimental research as well.

Students interested in political economic theory should acquire a strong background in mathematics or microeconomics.

In the last decade or so, political methodology has emerged as a distinct subfield of political science. 

Political methodologists study existing statistical techniques and develop new ways to use statistics to estimate and identify political effects and make sense of political data. Their role in the discipline is similar to that of econometricians in economics, whose main purpose is to understand the most efficient and accurate ways to test hypotheses and analyze data.

In the past, most political methodologists maintained a strong substantive focus in one of the traditional subfields while also working on questions of political methodology. Increasingly, however, political methodologists are less attached to a traditional subfield and focus primarily on improving the discipline's ability to make causal inferences from data.

The department has become one of the discipline’s leaders in the area of mathematical models of political institutions and collective behavior, often referred to as “formal theory" or "game theory."

The department is a leader in another emerging methodology, the use of field experiments to study political outcomes. The use of randomized control trials conducted in the field has influenced social science research generally over the last decade, and the department is at the forefront of this development. Scholars in the department have used field experiments to study issues such as political participation in the United States and dispute resolution in Africa. Research in experimental methods complements other methods, including game theory, quantitative analysis, survey research, and qualitative methods.

Political theory has customarily consisted of the history of political thought and normative/systematic political theory, with the latter divided between Anglo-American and continental approaches, although this divide has eased in recent years.

Globalization has brought a sharp increase in interest in non-Western styles of political theory, in issues of constitutionalism and democracy across the globe, in global justice, and in comparative political theory. Columbia's political theory section is particularly strong in the history of political thought, in analytical political theory, in legal theory, constitutionalism, democratic theory, theories of human rights, and theories of justice. The group also has strength in the burgeoning new field of comparative political theory.

The department’s theory section is one of the leading groups in the country.