Originally: Front-runner Preval an ex-protege of exiled Aristide

GONAIVES, Haiti (CNN) — With police and U.N. peacekeepers standing guard, Haitians are heading to the polls Tuesday to elect a president from 33 candidates vying for power in a nation wracked with political instability.

Voters in the extremely poor Caribbean nation also are choosing a parliament in the first election since 2000.

Polls suggested former President Rene Preval was the favorite to succeed Jean-Bertrand Aristide, who has been in exile since his ouster in 2004.

Preval, who was president from 1996 to 2000 and a former Aristide protege, has distanced himself from the exiled leader during the campaign.

Other prominent candidates include wealthy industrialist Charles Baker and former President Leslie Manigat, ousted in 1988.

U.N. officials hailed the vote as a key step toward democracy

“What is at stake here is a transition. Not necessarily a transition, as we all want it to be, to democracy but a transition to something. Everyone has his own model,” said Gerald Le Chevalier, chief of the electoral section of the U.N. assistance force helping organize the elections.

If no one gains more than 50 percent of the votes, the top two candidates will meet in a March 19 runoff.

Struggle for peacekeepers

For U.N. forces organizing the election, every step has been a challenge. Frequent gunbattles in Haiti’s worst slums have forced them to travel in armored vehicles.

Some 7,500 troops and nearly 800 police in the U.N. stabilization force were helping Haitian police keep watch and attempting to preserve calm in the country, which long has suffered from widespread poverty as well as violence.

After several postponements, U.N. officials said they are confident the vote will move forward peacefully.

“These elections offer an opportunity for your country to move away from violence and uncertainty toward a future of peace and stability,” U.N. Secretary-General Kofi Annan said Monday, delivering a message issued in English, French and Creole.

“I call on all Haitians to participate and exercise peacefully their right to vote,” Annan said. “Every vote is crucial for the future of Haiti.”

Checkered political past

In a recent report on the polling, Human Rights Watch noted that “in the past, elections in Haiti have often been marred by violence, disorganization and fraud.”

The country’s political history has been turbulent.

In 1971, Jean-Claude Duvalier became Haiti’s “president for life” at 19 after the death of his father, François, but economic and political instability forced him out in 1986.

Aristide was elected president in 1990, but the Haitian military arrested him in September 1991 and then ousted him from the country. He returned to power three years later after the U.N. Security Council threatened an invasion of Haiti by a multinational force and military leaders agreed to step down.

After Preval held office in the late ’90s, Aristide won the 2000 election.

“The deeply flawed 2000 elections aggravated political and social tensions and exacerbated political polarization,” Human Rights Watch said.

An armed uprising in 2004 and pressure from the U.S. and French governments forced Aristide into exile.

U.S.-led forces went to restore order and then transferred power to a U.N. stabilization force.

Human Rights Watch said illegal arms still circulate in Haiti and “criminal gangs continue to terrorize people living in urban slums.”

CNN’s Morgan Neill and freelance reporter Amy Bracken contributed to this report.