BRAZIL IS living through one of the worst spikes of covid-19 infections that the world has yet seen. On Wednesday, it recorded 3,869 deaths, a record that represented almost a third of all the coronavirus fatalities in the world that day. No end to the wave is in sight: Thanks to the stunning incompetence of President Jair Bolsonaro and his government, only 2 percent of Brazilians have been fully vaccinated, and the lockdown measures needed to slow new infections, including from a virulent variant strain that emerged in Brazil, are virtually nonexistent.

Instead of fighting the coronavirus, Mr. Bolsonaro appears to be laying the groundwork for another disaster: a political coup against the legislators and voters who could remove him from office. With some in the congress threatening impeachment, and former president Luiz Inácio Lula da Silva emerging as a potent challenger in next year’s election, Mr. Bolsonaro this week fired the defense minister, and the top commanders of the army, navy and air force jointly left their positions.

No explanations were offered, but the defense minister, Fernando Azevedo e Silva, was known for his arms-length treatment of a president who referred to the armed forces last month as “my military.” Mr. Bolsonaro selected his former chief of staff to replace Mr. Azevedo e Silva, and he named a police officer close to his family as the new justice minister. The moves were enough to prompt six likely presidential candidates to issue a joint statement warning that “Brazil’s democracy is threatened.” “Bolsonaro’s clear backup plan,” wrote editor in chief Brian Winter in Americas Quarterly, “is to have as many men with guns on his side as possible in the event of an impeachment or an adverse result in the 2022 election.”

Though Brazil’s democratic institutions are relatively strong after more than three decades of consolidation, there is reason for concern. Mr. Bolsonaro has openly expressed his admiration for the military dictatorship that ruled the country in the 1960s and ’70s. An admirer of Donald Trump, he has adopted the former U.S. president’s tactic of warning of fraud in the coming election and demanding that electronic voting systems be replaced with paper ballots. He supported Mr. Trump’s claims of election fraud, and his son, a legislator who visited Washington on the eve of Jan. 6, expressed dismay that the assault on the Capitol did not succeed.

The congress in Brazil may move to impeach Mr. Bolsonaro for his abysmal management of the pandemic, including minimizing its seriousness, resisting public heath measures and promoting quack cures. But the United States and Latin American democracies must pay heed as next year’s election approaches — and make clear to Mr. Bolsonaro that an interruption of democracy would be intolerable. The Brazilian president has already greatly contributed to the worsening of the covid-19 pandemic in his own country and, through the spread of the Brazilian variant, around the world. He must not be allowed to destroy one of the world’s largest democracies as well.