The question menacing Brazil's election: Coup or no coup?

For months, Mr. Bolsonaro has attacked Brazil’s electronic voting machines as rife with fraud — despite virtually no evidence — and Brazil’s election officials as aligned against him. He has suggested that he would dispute any loss unless changes are made in election procedures. He has enlisted Brazil’s military in his battle. And he has told his tens of millions of supporters to prepare for a fight.

“If need be,” he said in a recent speech, “we will go to war.”

With its vote on Oct. 2, Brazil is now at the forefront of the growing global threats to democracy, fueled by populist leaders, extremism, highly polarized electorates and internet disinformation. The world’s fourth-largest democracy is bracing for the possibility of its president refusing to step down because of fraud allegations that could be difficult to disprove.

Yet, according to interviews with more than 35 Bolsonaro administration officials, military generals, federal judges, election authorities, members of Congress and foreign diplomats, the people in power in Brazil feel confident that while Mr. Bolsonaro could dispute the election’s results, he lacks the institutional support to stage a successful coup.