One of the biggest challenges for contemporary liberal democracy is how much political weight should be given to extended beliefs about facts that are in tension with established expert opinion. This tension is the source of epistemic populism, which locates the plebeian rebellion against the elites not in the moral but in the epistemic dimension. While epistemic populism calls for a radical democratization of knowledge, and praises commonsense, folk wisdom and personal experience, it shows skepticism towards rarified methods, confirmation bias controls, and mediated procedures of justified knowledge-claims. The dilemma for liberal political theory is that whereas it cannot succumb to epistemic populism, as it has traditionally endorsed the scientific project, it cannot similarly succumb to technocracy or scientism, as valid democratic reasons are beliefs generally held and indeed found in common sense. The article suggests that this is the more pressing populist challenge to liberal democracy, as current and looming crises such as the pandemic and climate change require governments to take a stand: either the give political voice to scientific skeptics or they justify state action on generally non-accessible epistemologies. This could be the scenario that resolves the old theoretical struggle between a liberalism of tolerance and diversity, on the one hand, and a liberalism of rational autonomy, on the other; while the former will accommodate forms of epistemic populism within its institutional ethos, the latter will insist in the polity’s capacity to acknowledge a universally valid knowledge-generator.