A sequence of four pivotal elections over the past two weeks in disparate regions of the world has inflicted significant setbacks on authoritarian leaders, and inspired renewed faith that democracy is more resilient than had been feared.

The elections in Brazil, Serbia, Israel and the US were held in widely varying circumstances with unique factors, but each showed the power of grassroots activism to produce surprises that pushed back against would-be autocrats and could perhaps begin to reverse a worldwide drift towards authoritarianism.

In Brazil, a surge in turnout in the second round of presidential elections on 25 October, fuelled by grassroots activism and the canny use of social media , stopped a far-right authoritarian movement consolidating its grip on the country, three weeks after it won control of Congress and established a strong lead in the contest for the presidency.

On the same day, thousands of miles away in Serbia, a grassroots movement led by students inflicted a shock defeat on a…