Students of comparative law have long argued that undermining judicial independence is electorally costly, and that the norms against interference uphold institutional checks and balances essential to constitutionalism. However, evidence from countries with robust judiciaries suggests that exposing voters to deficiencies in the legal process or the courts’ partisan leanings can reduce perceptions of judicial legitimacy, making such interference on part of would-be authoritarians more likely. The rise of populist politicians poses additional risks: by emphasizing judges’ unelected status and counter-majoritarian tendencies, populists may erode legitimacy, framing judges as part of a “corrupt elite” opposing “the people.” This rhetoric challenges liberal-democratic norms that limit state interference with individual rights. To test whether one observes the effects of partisanship and procedural fairness on voters’ perceptions of the courts outside the US context, and whether populist messages produce comparable effects, a pre-registered survey experiment is conducted in the context of Czechia, a country that, until recently, has had both a populist executive and a strong and independent Constitutional Court. The study presented respondents with vignettes describing an important electoral ruling of the Czech Constitutional Court, embedding messages that highlighted judges’ unelected status, the ruling’s procedural irregularities, or its partisan implications. Contrary to expectations, findings show no significant effects of any message type on perceptions of judicial legitimacy. The results of the study suggest that the marginalization of robust judiciaries in backsliding democracies may be a largely elite-driven institutional process, with uncertain electoral payoffs.