“Transnational demoi-cracy” is conceived here to not only encompass legal, governmental and institutional devices for bridging nationally fragmented ‘demoi’ but to include in particular the cross-border interlinking by civil society and the public sphere. In Bohman’s terms, transnational demoi-cracy requires the “exercise of communicative power across demoi”. In the global context, a growing body of studies has critically taken stock of the new “discursive arenas that overflow the bounds of both nations and states” (Fraser). Regarding Europe, normative expectations are still questioned as to whether and to what extent mass mediated “public spheres today conceivably generate public opinion in the strong sense of considered understandings of the general interest that has been filtered through fair, inclusive, and critical argumentation, open to everyone affected? And could public spheres today conceivably bring such public opinion to bear to constrain sovereign powers…? What sorts of changes (institutional, economic, cultural, and communicative) would be required even to imagine a genuinely democratic (or democratizing) role for transnational public spheres under current conditions?” (Fraser 2005). The paper develops empirical indicators and draws on a comparative data set to critically assess these normative expectations, that is, to establish how the national media systems selectively filter the transnational scope and the deliberative quality of European political communication. The analysis consists of three parts: a normative-conceptual one, a methodological part and a comparative empirical study of national mass media performance in covering the EU’s treaty reform and ratification (2004-9).