This article uses one case study to explore the use of criminal hate speech provisions against populist politicians. In a high-profile Finnish case, a populist politician was found guilty of hate speech after a four-year criminal process. Though the prosecution was ultimately successful, the various problems with the case helped boost the political popularity of the accused who was turned into a well-known public figure and member of Parliament. The case might thus be seen to warn against tackling populist politicians by means of criminal law. However, further analysis of the political context and a comparison with the Dutch prosecution against anti-immigration politician Geert Wilders complicate this conclusion. This article examines the consequences of hate speech prosecutions of politicians and sheds light on the conditions under which they can achieve (some of) their aims. The case also has lessons for other jurisdictions about when hate speech prosecutions of politicians are likely to be successful in terms of countering prejudice and disempowering those who spread it for electoral purposes.