America’s Electoral System Is Vulnerable. It Can Learn From Brazil.

For months before Brazil’s presidential election runoff on Oct. 30, far-right incumbent Jair Bolsonaro questioned the integrity of the country’s electoral institutions and public officials, building a case to challenge a potential defeat at the polls. But when Bolsonaro lost to Luiz Inácio Lula da Silva, those very institutions preempted and ultimately shut down any attempts to undermine confidence in the plebiscite. In the wake of the election, Bolsonaro was silent.

Bolsonaro is no fragile Amazon flower. Strident, bombastic, and shameless, he has drawn constant comparisons to former U.S. President Donald...