Will the coronavirus be Jair Bolsonaro’s kryptonite?

Under strict lockdown measures, citizens in several parts of Italy have used their windows and balconies for singing and dancing—heartwarming attempts to lift morale in the country that has become the new epicenter of the Covid-19 pandemic. In Brazil, however, these same windows and balconies are being used as protest venues, directing their outrage squarely at the Jair Bolsonaro government.

For the past three days, at 8 pm sharp, Brazilian urban centers have banged pots and pans in protest of President Jair Bolsonaro and his erratic management of the Covid-19 crisis. This form of demonstration is known in Brazil as a panelaço—from panela, the Portuguese word for pot—but is more widely referred to as the Spanish word cacerolazo, being generally more common in other South American countries.

Many see these protests as evidence that the president is growing more and more isolated and that his support base is waning. According to consultancy Atlas Político, which published the first opinion poll since cases of Covid-19...