I am pretty sure this is regards to BRICS and not about communists or how Brazil is governed. I get that it may not be the best nation politically, but USA didn't do anything about it, all the way until BRICS and now they are retaliating for what BRICS İs doing.
He already did this with Russia and China, now he is aiming at Brazil, and could even increase it more in the future. Dude knows that going to a war with any nation is costly and dangers his position, but making economical warfare is free for him and he is allowed to do. So instead of actually fighting, he is just increasing tariffs on whoever he wants, makes more sense to him and easier to handle the paperwork too, he doesn't get that much backlash because of it neither.
However you know this is not only politics by BRICS, I think it is too much personal and political. 50% tariff is now official on Trump's lawsuit against Brazil's Bolsonaro. Something like witch hunt & for importing coffee, orange juice, beef, & aircraft set a 42 billion trade target. Though BRICS are kinda retaliatory, but you know it is more than a political saga, something like picking up leverage to stay away from military hostility. It is obvious our inflation rate will climb and also shake up world market. More worst thing is Brazil is imposing groundworking reciprocal tariffs, so now we need soft diplomacy from both sides to defuse tensions. I could not consider it as cheap politics or easy leverage, both countries economy and consumers will get hampered.