Hate speech prosecution of politicians is a common phenomenon in established democracies. Examples of politicians tried for hate speech include Nick Griffin in Britain and Jean-Marie Le Pen in France. Does hate speech prosecution of politicians affect the electoral support for their party? This is an important question, as the parties involved typically are controversial, often accused of stirring up political cynicism or political violence. The relevant literature has largely ignored this question, however. In this article, we use data from a representative sample of Dutch voters interviewed before and re-interviewed after the unexpected court decision to prosecute MP Geert Wilders. We demonstrate empirically that the decision substantially enhanced his party’s appeal. This resulted in an immediate increase in support for the party by one to five percentage points among those who are moderately in favour of the assimilation of ethnic minorities into Dutch culture. In addition, the evidence suggests that the decision contributed to the party’s subsequent electoral lift-off. Our findings call for investigations into the electoral effects of legal proceedings against political actors in democratic systems worldwide.