BRASILIA, Oct. 23 (Xinhua) -- As Brazil's presidential race heads into the homestretch, conservative Social Liberal Party (PSL) candidate Jair Bolsonaro takes a commanding lead over rival Fernando Haddad of the left-leaning Workers' Party (PT).

With just days left before the Oct. 28 run-off, Bolsonaro has a 14 percent to 20 percent advantage, according to the latest polls.

Surveys show that Bolsonaro has the support from 57 percent to 60 percent of the voters, compared with 40 percent to 43 percent for Haddad.

The outlook is grim for Haddad, who has described this race as a dispute between democracy and authoritarianism, given Bolsonaro's hardline campaign platform.

History shows a second-placed candidate has never been able to turn things around and win a presidential runoff in Brazil.

Additionally, Brazil's progressive sectors failed to unite behind Haddad, who was primarily hoping for an endorsement from ex-President Fernando Henrique Cardoso. While Cardoso repeatedly expressed concern about Bolsonaro's outspoken right-wing views, he declined to support the PT candidate.

As Bolsonaro rose in the polls, Haddad changed tactic, deciding to distance himself from the PT's original candidate and spiritual leader -- ex-President Luiz Inacio Lula da Silva, who is currently serving a 12-year prison term for corruption. He also admitted the PT made mistakes.

But the change in strategy made little difference.

Bolsonaro has maintained his lead even after allegations surfaced last week that his supporters paid millions to spread fake news via social networks.

The nation's top election body, the Superior Electoral Court (TSE), opened an investigation into the charges but otherwise took no action, saying it was confident that Sunday's voting will go off without a hitch.

In another incident, Eduardo Bolsonaro, the candidate's son, was caught on video suggesting the top judicial body, the supreme court could be easily shut down with just "a corporal and a soldier."

The remarks angered supreme court judges, who said it was "irresponsible" and evocative of a "coup." Bolsonaro apologized on behalf of his son and expressed his respect for the high court.

During a campaign rally in Sao Paulo on Sunday, Bolsonaro again sparked outcries, saying his "red" adversaries should either leave the country or go to prison, including Haddad.

But these incidents have failed to make a dent in his popularity.

Aware of his strong lead, the PSL candidate refused to take part in traditional televised presidential debates, admitting it was a campaign strategy. His running mate Hamilton Mourao, a retired general, and economic adviser Paulo Guedes, have similarly kept a low profile.

Unless something comes up that could have a major impact on voters, everything points to a decisive Bolsonaro victory on Sunday.