People call them les marchands jamais do-do, the vendors who never sleep. Smiling, they pad Champ de Mars, Port-au-Prince's central esplanade, at all hours of the night or day, selling mangos, wood carvings and directions around town.

"How can they be so happy with their lot?" asked a wealthy Haitian businessman. "They are always walking in front of my office. I never know where they are going. No one knows. I wonder if they know themselves. But they always look content."

On the outside, at least, Haitian street people indeed seem strangely content in a country where they have every reason to be angry and desperate. A little boy, when handed the equivalent of 20 cents, literally jumps for joy. An older beggar smiles when refused a handout and turns to wait for the next blanc, or white person, to walk by.

Port-au-Prince has doubled its population to 1.5 million in the last decade, and many of its poor sleep Calcutta-style on the sidewalk. At least half the country's 6 million inhabitants are unemployed, so they have nowhere to go in the daytime either. Statistically, the average annual income is about $250 a person. Actually, 1 percent of the people receive 45 percent of the income, making real life for the street people tougher than the numbers sound.

In these conditions, it is a testament to the good nature of the Haitian people that violent crime and theft are so rare here as to be almost nonexistent. Foreign residents often leave their cars parked downtown without locking them, and men and women walk in the street at night unafraid.

Perhaps the Haitian national character also helps explain why there is so little visible opposition to the dictatorial government of President-for-Life Jean-Claude Duvalier. That, and the fact that most of what the government does passes over the heads of Haiti's poor in any case.

An estimated 80 percent of the population is illiterate. Many of the 4.5 million Haitians outside Port-au-Prince live in villages and hamlets linked by rudimentary roads if linked at all. For them, the name of the man in the gleaming white presidential palace in the capital matters little. The Information Ministry has put up billboards around Port-au-Prince featuring excerpts from Jean-Claude's most memorable speeches--all in French, understood by only 10 percent of the mostly Creole-speaking population.

Such underdevelopment also helps to explain why Haiti is the poorest country in the hemisphere and one of the poorest in the world. A Foreign Ministry official complains, for example, that to make sure his correspondence is sent he has to stand over the typist and take letters down personally to the ministry mailroom.

One thing that seems to work well is the Volunteers for National Security, the Tontons Macoutes political police that has contributed mightily to Haiti's reputation for repression and brutality.

The Tontons Macoutes are estimated to include 9,500 paid agents, some in uniform and others in dark glasses. But a foreigner who has been studying Haiti for the last 15 years reckons that counting the number of Haitians who contribute to the police network by occasional freelancing could multiply that number several times.

When their brothers, cousins and friends are added to the tally, he says, "what you really have is an armed political party with members all over the country." Celebrating the 22nd anniversary of Duvalier family rule, Jean-Claude three years ago called the militia "the linchpin of my government."

His father Francois founded the Tontons Macoutes on coming to power in 1957 as a reliable force for his black revolution to balance off the army, then dominated by the mulatto class that had run Haiti during most of its period of independence. Since then, a black middle class has also emerged, but the Duvalier philosophy still represents the triumph of Haiti's poor black majority over a wealthy mulatto elite.

Jean-Claude, who took over from his father at age 19 in 1971, strained the family image slightly with his marriage three years ago to Michele Bennett, the divorced daughter of a prominent mulatto merchant. Aside from her light-colored skin and two children from her previous marriage, Michele had a drawback: the father of her first husband, also a mulatto, is reputed to have sought to assassinate Jean-Claude's father.

According to sources familiar with palace doings, Jean-Claude's mother and other diehard Duvalieristes opposed the union, but the young president-for-life was determined to wed the former model and got his way.

No outsider knows for sure what goes on behind the palace doors, because the ruling family commands the reverence usually reserved for royalty, and the mystery stirs up frequent rumors.

According to one making the rounds, Michele could not be the mother of the two-month-old heir, Jean-Claude II, because she had her Fallopian tubes sealed during her first marriage. The photos showing her in flowing maternity dresses last winter were faked, the rumor goes, to make Haitians think they have a genuine heir.

As far-fetched as it sounds, the rumor has people counting back to compare the first pregnancy photo with the birthdate--and reaching 10 months.