On Thursday, the Brazilian Supreme Court did what the U.S. Senate and federal courts tragically failed to do: bring a former president who assaulted democracy to justice. In a historic ruling, the Supreme Court voted 4 to 1 to convict ex-President Jair Bolsonaro of conspiring against democracy and attempting a coup in the wake of his 2022 election defeat. He was sentenced to 27 years in prison. Barring a successful appeal, which is unlikely, Mr. Bolsonaro will become the first coup leader in...