Since March, the son of the former Brazilian president Jair Bolsonaro has been roaming the halls of the White House. Eduardo Bolsonaro, 41, is a sitting Brazilian congressman, but his latest job has been to convince U.S. officials that a dangerous Brazilian Supreme Court justice wants to throw him and his father into prison, simply for fighting against what they claim was a stolen election. And in multiple visits to Washington over the past several months, he has found a sympathetic audience. “This is nothing more, or less, than an attack on a Political Opponent — Something I know much...