TRANSNATIONAL seeks to explain the intensity of polarisation on immigration, Europe, and climate change. It will combine insights from political cleavage theory with those on identity theory and social networks to examine transnational polarisation through surveys, natural experiments, and interviews. The project leaders are Liesbet Hooghe and Gary Marks.

Perhaps the most pressing challenge facing Western democracies is to come to grips with a profound shift in the structure of political conflict. Alongside the left-right divide over the role of the state in the economy, new issues related to the nation, self-rule, and multi-culturalism have come strongly onto the agenda. One side embraces open societies, cultural diversity, and international governance; the other considers these as a threat to their national community and their way of life. We describe this as a transnational divide and believe that it signifies a critical juncture in the political development of Europe no less decisive than the previous junctures that Lipset and Rokkan detect in their classic 1967 article.

The science of politics has progressed as researchers have sought to explain this phenomenon. We have a sophisticated understanding of how voters position themselves on these new issues, and we now know much more about how political parties strategise in electoral competition. A growing literature has shed light on the spatial dimension of the transnational divide, and in particular, on the rural backlash against globalisation.

These advances raise fundamental questions.

  • How can one explain the affective polarisation that has erupted among political activists and in the wider public?
  • Is the conflict motivated by the development of group identities?
  • What is the role of digital and face-to-face networks in consolidating solidarity on either side of the divide?
  • Are we witnessing a new political cleavage in the history of Western society?

These are the questions the project seeks to answer.

The challenge is both theoretical and methodological. We need to theorise the dynamic interplay between individual characteristics and social networks. Beyond the effect of individual demographics in predisposing political attitudes, little is known about how social interaction shapes affective polarisation. This is problematic both for our understanding of public opinion on transnational issues, and, more generally, for building the micro-foundation for a theory of political conflict.

One reason why we know so little about how social interaction shapes a person’s response to major change is the difficulty of gaining causal leverage in the face of considerable observational complexity. The phenomenon of a rising political divide is a unique opportunity to investigate the political effects of societal transformation as it is taking place, yet the effects of transnationalism are diffuse and hard to identify. It is difficult to tell whether we are witnessing the response to particular issues—chiefly immigration—or a general phenomenon that encompasses a range of issues.

TRANSNATIONAL responds to both challenges by a) targeting citizens and activists in specific localities with varying levels of exposure to transnational effects; b) investigating social interaction on a range of transnational issues; c) embedding local natural experiments within representative national surveys; and d) using panel surveys and semi-structured interviews to assess the temporal interaction of identity formation, affective polarisation, and social networking.

The research is funded by a five-year advanced ERC grant #885026 to Liesbet Hooghe. TRANSNATIONAL was kicked off in January 2021. Project leaders are Liesbet Hooghe and Gary Marks.


Research team

Liesbet Hooghe, Research Professor, EUI
Gary Marks, Research Professor, EUI
Julia Schulte-Cloos, Postdoctoral Researcher, EUI

Project manager

Jo Wielgo

Visiting Fellows

Ashley A. Anderson, Assistant Professor, UNC Chapel Hill (2022)
Nicoló Conti, Professor, Unitelma Sapienza University, Rome (2022-2023)
Ruth Dassonneville, Canada Research Chair in Electoral Democracy, University of Montreal (2021-2022)
Pieter de Wilde, Professor, Norwegian University of Science and Technology at Trondheim (2021)
Gabriele Magni, Assistant Professor, Loyola Marymount University (2022)
Christina Zuber, Professor, University of Konstanz (2022)

Transnational ERC Associates

Jeremy Ferwerda, Assistant Professor, Dartmouth College
Stephanie N. Shady, PhD. Graduate, UNC Chapel Hill



  • Liesbet Hooghe, Gary Marks, Stephanie Shady. “Mensheviks, Bolsheviks, and the divide on the religious right: Conservative pastors and the use of force.” Working Paper.
  • Liesbet Hooghe and Gary Marks, “The Social Roots of the Transnational Cleavage: Sex, Education, and Occupation.” Working paper.
  • Gabriele Magni, Jeremy Ferwerda, Liesbet Hooghe and Gary Marks, “Circles of Solidarity: COVID impact on In- and Outgroup perceptions in Italy.” Working paper.
  • Cecilia Martinez-Gallardo, Nico de la Cerda, Jonathan Hartlyn, Ryan Bakker, Liesbet Hooghe, and Gary Marks, “Revisiting Party System Structuration in Latin America and Europe: Economic and Socio-Cultural Dimensions.” Working paper.
  • Tobias Lenz, Bes Ceka, Liesbet Hooghe, Gary Marks, Alexander Burilkov, “Discovering Cooperation: A Theory of Endogenous Institutional Change in International Organizations.” Working paper.
  • Gary Marks, Liesbet Hooghe, David Attewell, Jan Rovny, and Marco Steenbergen. The Social Bases of Political Parties: A New Measure and Survey,” British Journal of Political Science, Online first, Feb 2022.
  • Jan Rovny, Ryan Bakker, Liesbet Hooghe, Seth Jolly, Gary Marks, Jonathan Polk, Marco Steenbergen, Milada Anna Vachudova, “Contesting Covid: The Ideological Bases of Partisan Responses to the Covid-19 Pandemic.” European Journal of Political Research
  • Seth Jolly, Ryan Bakker, Liesbet Hooghe, Gary Marks, Jonathan Polk, Jan Rovny, Marco Steenbergen, and Milada Anna Vachudova, “Chapel Expert Survey Trend File, 1999-2019,” Electoral Studies (online first Nov 2021).
  • Liesbet Hooghe and Gary Marks, Multilevel Governance and the Coordination Dilemma. In Arthur Benz, Jorg Broschek, and Markus Lederer, eds.  A Research Agenda for Multilevel Governance, Edgar Elgar, 19-36.