The novel coronavirus is an unprecedented social and political challenge and has potentially created new dimensions of political conflict in many (if not most) countries. One key consequence of the pandemic is that many countries have seen an increase in the salience of competent governance. To explore the impact of COVID-19 on electoral politics, we present a theoretical framework where politicians compete over ideological platforms but can be distinguished by their competence. Our model features both uncertainty about the location of the representative voter and valence uncertainty. We first show that absent direct concerns about competence, political polarization is positively related to ideological uncertainty. An increased salience of competence for voters (brought on by a social crisis like COVID-19) leads to greater ideological polarization among politicians, and this increase is concentrated in districts with low ideological uncertainty. We examine the implications of our theory using data from Brazilian municipality elections. Using a difference-in-differences methodology we find that COVID-19 leads to increased political polarization in Brazil, but that this increase is concentrated in areas where the partisan leaning of voters is relatively certain.