"This is a really uphill battle for Flavio Bolsonaro," said Americas Quarterly's editor-in-chief to the news agency.
A digital push helped Brazil's leader notch an October 25 win. But economic and legislative hurdles and difficult U.S. ties lie ahead.
The president defied polls and is set for a fourth term, despite Flávio Bolsonaro's claims of irregularities.
The opposition leader's comeback adds to pressure for setting an electoral timetable.
"El cambio para Nicaragua tiene que venir desde adentro, con decisiones de los propios nicaragüenses", dijo el vicepresidente de AS/COA al periodista.
The question of why two nations "have of late walked such similar paths has set off a vigorous debate," writes AS/COA's vice president.
Can Flávio Bolsonaro maintain momentum or will President Luiz Inácio Lula da Silva mount a comeback in the October 25 runoff?
