By Vivian Sequera and Mayela Armas
CARACAS (Reuters) - To the sound of samba drumming and catchy jingles, Venezuelan opposition candidate Mirlenys Palacios campaigned with dozens of supporters in the narrow streets of a hillside neighborhood of Caracas - something unthinkable in recent years.
Venezuela's opposition has boycotted elections in the South American nation for the past four years, arguing that a fair vote was impossible due to vote rigging and intimidation by violent gangs loyal to leftist President Nicolas Maduro, known as colectivos.
But, frustrated by the failure of U.S. sanctions to dislodge Maduro, and emboldened by the presence of election observers from the European Union, the main opposition parties have decided to return to the ballot box.
Elections on Sunday will determine over 3,000 local seats - including 23 state governors, mayors, and municipal councils - with some 21 million Venezuelans eligible to vote.
Guarataro, a poor district in the west of the sprawling capital, has long been considered a stronghold of the ruling party. For years, Caracas' hillside barrios were fiefdoms of former president Hugo Chavez and his hand-picked successor, Maduro.
However, the popularity of 'Chavismo' has been eroded by hyperinflation, corruption, and economic collapse, worsened by the U.S. sanctions.
Campaigning this week in Guarataro, Palacios, a 50-year-old activist running for a local councillor seat, and other opposition candidates met no resistance from Maduro's supporters.
"What did I tell you?" Palacios told reporters, shouting through her mask amid the din of campaign music. "This neighborhood does not belong to Chavismo."
But the opposition's return to the electoral fray is no guarantee of success. Its leadership remains deeply fragmented, with some major parties skeptical about participating and smaller ones refusing to field candidates, insisting the vote will not be fair.
Since winning legislative elections in 2015, Venezuela's opposition parties have seen their political influence curtailed by Maduro's government, which created a rival government-controlled Assembly to "restore peace" after months of protests.
The opposition denounced fraud after the government won 2017 local elections, and boycotted the presidential vote in 2018 and a congressional ballot two years ago.
Now, the presence of EU observers for the first time in 15 years has played a part in lowering political tensions, said Andres Caleca, a political analyst and former president of the National Electoral Council (CNE).
"Where are the colectivos? Hidden. Hidden because there is an international observation mission," he said.
Venezuela's information ministry did not respond to a request for comment.
Participants in Sunday's elections include members of Popular Will, the party of opposition leader Juan Guaido, who is recognized as Venezuela's rightful president by Washington and several western allies that do not recognize Maduro's 2018 re-election. He has been derided as a U.S. puppet by Maduro.
Some Maduro opponents fear the freedom being given to the opposition to campaign is part of a government strategy to deliberately lower political tensions and so discourage participation.
"It wants abstention," said Henrique Capriles, a former opposition presidential candidate during a tour of the central state of Miranda alongside opposition electoral hopefuls.
In previous elections, such as the 2015 legislative vote, high turnout led to opposition gains. Datanalisis, a local consultancy, estimated in October that if abstention tops 55%, the ruling party would win 18 of the 23 state governorships.
Even with a strong turnout, analysts predict the opposition may struggle to improve on the four governorships that they won in 2017's local elections. With that in mind, some opposition leaders have hit the campaign trail to try to drum up support and to appeal for greater unity.
"What hurts the opposition the most is the dispersion of the opposition vote," said Capriles.
Those divisions help the ruling party, Caleca agreed.
"I do not see anywhere a resounding triumph of the opposition," he said.
And the Socialists are able to call on significantly more resources.
At a rally in Caracas' central Plaza Bolivar, former interior minister Carmen Melendez - the Socialists' candidate for mayor - presented her policies to a crowd of some 200 people on a large screen using slick videos.
There were dozens of security guards and the square was decorated with chairs dressed in the yellow, blue and red colors of the Venezuelan flag.
Given the Socialists' powerful electoral machinery, analysts expect Melendez, a member of Maduro's inner circle, and other senior government candidates to win key races.
"You are going to govern in Caracas," she told the crowd, which reserved its most enthusiastic cheer for a promise of free wifi in public squares and parks.
Despite the concerns, many Venezuelans are determined to exercise their right to vote at the first ballot offering a real choice since 2017.
"This is a rich country where nothing works and I will vote on November 21," said Diana Bracho, a 36-year-old public employee who lives in a rural area of Miranda controlled by the ruling party.
(Reporting by Vivian Sequera and Mayela Armas, Additional reporting by Anggy Polanco in San Cristóbal, Editing by Daniel Flynn and Rosalba O'Brien)