Introduction : how the failed political messaging of moderate political actors strengthens populist radical right parties -- The riddle : why are some populist radical right parties more successful than others -- State of research : linking social theory with comparative politics -- Research design : ensuring high validity and high reliability under the auspices of comparative case studies -- Empirical results: why populists win or lose : a two-level theory -- The Netherlands : the PvDA’s pyrrhic victories or, waiting for Pim Fortuyn -- Sweden: how the Liberals (FP) gave birth to the Swedish Democrats (SD) -- Germany : how a conservative compromise between CDU/CSU and SPD blocked the popuist radical right parties REP and Schill -- Generalizing the findings : explaining the rise of UKIP and the AfD -- Conclusion : it’s political messaging, stupid!