Steve Bannon, the former top adviser to U.S. President Donald Trump, was arrested on fraud charges this week. Strangely, that piece of news appears to have generated more buzz in Brazil than in the U.S., where Mr. Bannon is no longer seen as a major political player. But in Brazil, his connections to the Bolsonaro clan have turned him into a bogeyman for the Brazilian left — which lost no time in foretelling the backslide of the far-right in the country.
Many in Brazil sincerely believe that Jair Bolsonaro’s rise to power was orchestrated by Mr. Bannon, after they...