Brazil’s 2022 campaign has already started on the streets and online

A group of conservatives in Rondonópolis, a city in the Center-Western state of Mato Grosso in the heart of Brazilian soy country, erected a billboard last month featuring a massive photo of former president and 2022 presidential frontrunner Luiz Inácio Lula da Silva. “Here, this crook is known as a ‘traitor of the homeland.’ Out…  Cursed one!”

While candidates are strictly forbidden from distributing electoral material before August 16 (the election will take place on October 2), citizens have begun to decorate their cities with billboards in support or repudiation of politicians — usually Lula or President Jair Bolsonaro, the two most popular and polarizing figures in Brazil.

These efforts can be organic and spontaneous in some cases. But they are usually anything but.

Marketing consultant Uca Barreiro spends about six hours every day browsing the hundreds of pro-Bolsonaro groups he manages on WhatsApp and Telegram. He claims his groups combine more than 20 million monthly views — which would give him an audience far bigger than that of Brazil’s most traditional magazines.

When doing research for this article, I joined a WhatsApp group called “President that gets it done,” number 230. Meaning that there were 229 other groups broadcasting the same content — but that had reached their 256-member cap. A few hours later, number 230 reached the member cap, and number 231 was created. In the groups, Mr. Barreiro basically reposts content created by government agencies, adding his own brand and slogan.

To manage this operation, he receives sponsorship...