Free Party presidential candidate Xiomara Castro de Zelaya greets supporters during her closing campaign rally in Tegucigalpa, Honduras. (Eduardo Verdugo/AP)

In the country that has become North America’s biggest basket case, Sunday’s presidential elections are a chance for a fresh start and a path toward greater stability and security.

Or they could send Honduras deeper into the ditch.

Such is the fear of the international observer missions deployed here in large numbers this weekend — the State Department, the Organization of American States (OAS), the European Union and others. It is also on the minds of Hondurans stocking up on bottled water, food and supplies as they gird for the worst, as if bracing for a hurricane.

With three major presidential candidates, eight political parties, a polarized electorate divided sharply along class lines and a rickety electoral apparatus vulnerable to fraud, there is plenty to dread.

Honduras has earned the unfortunate distinction in recent years of having the world's highest homicide rate, with 20 murders a day in a country of only 8 million. Drug traffickers have made it the landing pad of choice for smugglers’ flights from South America; U.S. anti-narcotics agents estimate that 87 percent of the cocaine on U.S. streets touches down first in the jungle airstrips of Honduras.

The country's rampant killings, intractable corruption, feeble institutions and weak economy have driven growing numbers of illegal migrants to the United States in recent years, and a new crisis here could push more people north.

It’s one reason that U.S. diplomats describe Sunday’s outcome as something like the opposite of a Las Vegas tourism pitch: What happens in Honduras doesn’t stay in Honduras.

Although a stable, relatively smooth election could lead to increased U.S. trade and more legal migration, “a negative outcome means that people who don’t feel safe and can’t provide for their families will try to come without a visa,” said one high-ranking U.S. Embassy official.

The country is a lesson in the risks of democracy interrupted. Honduras was already wobbling in June 2009 when President Manuel Zelaya was deposed in a coup, with soldiers pulling him from his bedroom and putting him on a plane to Costa Rica in his pajamas.

Zelaya was allowed to return two years later, and the leftist, Stetson-wearing, mustachioed rancher remains the country’s pivotal political figure. Although not a candidate in this election, he has done little to conceal his prominent role in the campaign of his wife, Xiomara Castro de Zelaya. Their newly founded Free Party has upended the country’s two-party status quo and energized large sectors of the urban poor, rural peasants and students.

But Castro, Zelaya and their supporters could send Honduras into another downward spiral if they cry fraud after a loss and take to the streets.

“The country has been dominated for too long by foreign powers and an oligarchy of families,” said Castro supporter Efraim Reyes, an attorney carrying his briefcase through the capital’s Central Park, where Sandinista folk songs played from a Free Party campaign tent opposite a Burger King with a “Casa del Whopper” sign. “They don’t tolerate anything that will affect their interests,” he said.

Castro, 54, is running on a campaign pledge to convoke a special assembly that would rewrite Honduras’s constitution and “re-found” the country. It was the same type of talk that spooked the business class during her husband’s presidency, stacking up forces against him.

One of the 2009 coup’s biggest backers is now Castro’s main rival for the presidency, Juan Orlando Hernández, 45, the leading conservative candidate and former president of Congress. He wants to impose martial law by deploying soldiers to battle Honduras’s street gangs and drug traffickers, and Hernández appears in campaign commercials flanked by troops, telling the camera he’ll do “what needs to be done” to wipe out criminals.

His billboards are everywhere in the capital, seemingly accounting for most of the campaign advertising here.

A third candidate, Mauricio Villeda, 65, has been rising in the polls and has emerged as a dark horse in the race, particularly as undecided voters look for a moderate alternative to Castro and Hernández.

“He’s the only one who has run a clean campaign, and he doesn’t try to insult anyone,” said Ruth Ortega, a housewife in the capital.

Honduras has no runoff system, and with the three leading candidates polling between 20 and 30 percent, it’s possible that Sunday’s winner could squeeze out a victory with a bare plurality of the votes. The entire Honduran Congress is also up for reelection, and observers are expecting a record turnout.

Yet a narrow margin of victory and irregularities in the balloting could taint the entire process.

Honduras has minimal electoral infrastructure, and Sunday’s votes will be counted by representatives of the political parties, not impartial poll workers. This method was designed for the two-party system that dominated here for decades, but some of the eight parties in this election don’t have the resources to deploy campaign workers across the country.

Tally sheets of the votes are supposed to be scanned and sent electronically to election authorities, but at least 10 percent of polling stations don’t have electricity or Internet access. The pronouncements of international observers — especially the OAS — will be critical in shaping perceptions of the election’s integrity.

“I think if things go wrong, there’s potential that Honduras will be further weakened, and instability and weakness is a magnet for organized crime,” said Eric L. Olson, a Central America policy expert at the Woodrow Wilson Center in Washington.

“It represents risks for the region and the U.S., because any country that is spiraling out of control and can’t deal with internal problems becomes an international problem,” he said.

At least 16 Free Party activists and candidates have been slain since summer, according to rights groups, more than all the others parties combined.

Dana Frank, a Honduras scholar at the University of California at Santa Cruz, said the vote will be “a new test” for the Obama administration, which initially denounced the 2009 coup against Zelaya but later recognized the post-coup government.

This time around, with his wife in the race, voters have the chance to determine how they really feel about Zelaya, and whether they want the couple to put the country back on the pre-coup path that aligned Honduras with Venezuela and other U.S. rivals in Latin America.

“Should Castro win, the region will be watching closely to see whether the U.S. can work amicably with a government not of its choosing or whether the U.S. remains stuck in a Cold War mind-set when it comes to Central American politics,” said Frank.