After the first couple of weeks of the runoff stage, it seemed that nothing would be able to curb Jair Bolsonaro ‘s momentum. His allies were even talking about making a push to win the election by the widest margin ever recorded (62 percent). But, as the late Brazilian poet Carlos Drummond de Andrade once wrote, “there was a stone in the middle of the road.”
That stone was a Thursday report by Folha de S.Paulo, Brazil’s largest newspaper, showing that a network of companies illegally hired social media companies to send hundreds of millions of messages to voters attacking Mr. Bolsonaro’s rival, the Workers’ Party’s Fernando Haddad. Each “pack” of messages reportedly cost up to BRL 12 million. The scheme was illegal because it wasn’t on the books and because companies are simply not allowed to contribute to political campaigns.
The news cycle kept going. First, WhatsApp announced it had deleted over 100,000 accounts linked to spamming and illegal activity. Then, Facebook (WhatsApp’s parent company) banned 68 pages and 43 accounts known for posting fake news in...