Constitutionally, Cuba's political system is clearly defined, and to most Cubans is clearly democratic, but to Americans who dig beneath the totalitarian surface, it seems complex and convoluted. Most would agree, however, that it can be summed up in one word: Fidel.

He is the world's longest ruling leader of a country. His word is law. Any criticism is whispered.

While visiting with a group of Cuban journalists last month in Santiago de Cuba, the island's second largest city, on its southeastern shore, one American newspaper executive asked, "Are you free to criticize Castro?"

The answer was an unequivocal "no." But a Cuban journalist elaborated. "When Fidel makes a mistake, he admits it. Then we are free to report that."

There wouldn't be much in American newspapers if we had that kind of limitation here.

In theory, candidates for elective office in Cuba's legislative branch, the local, regional and national assemblies, are chosen by neighborhood organizations, CDRs, Committees for the Defense of the Revolution. Everyone age 16 and older belongs to one, and, as political units, they function much like our precincts. Of course, the involvement of CDRs in Cuban life goes far beyond choosing political representatives. They are social units, neighborhood (and neighbor) watches and, of course, defenders of the revolution - the party line. The CDRs' cartoonish icon is a four-eyed character who appears to hold a walkie-talkie. I didn't discover its intended meaning to Cubans, but to me it seemed all too clear: everyone watching everyone and, if necessary, reporting everything.

CDRs are not, however, directly related to the Cuban Communist Party. While all adults belong to a CDR, fewer than 1 percent are members of the Communist Party, by law the only political party in Cuba. Membership is not mandatory for political or bureaucratic office, but it can't hurt.

Our tour guide/handler, Renier Rodríguez, told us he's a Communist, one of five party members among the 100 guides in Havanatur, the government agency overseeing our visit.

As we rode through Havana and across the island, our guide, "Reney," as we'd dubbed him, tried his best to explain Cuba's democracy and freedoms.

He was polite and patient - and tolerant of our skepticism and criticisms.

"I'm not very good in politics, but I don't think you will convince me of your system," he said.

After traveling together for nine days, many hours on a bus while covering some 800 miles around the island, and having numerous discussions, serious and humorous, I'm sure we didn't.

Reney is 33 - born 12 years after the revolution. He's never been to another country. But his job allows him much more access to the outside world, through contact with tourists and the occasional overnight in a tourist hotel, than the average Cuban enjoys. Except in those tourist hotels (for foreigners only and occasionally tour guides when no other accommodations are available nearby), there is no CNN, no satellite TV, just Cuban TV. U.S. radio and TV signals beamed to the island are jammed, although some, we're told, get through. There are no foreign magazines or newspapers. Books must be government-approved. Internet access is limited and monitored.

Like Reney, most Cubans were born after the revolution and have no detailed knowledge of other ways of life, just a general awareness that there is economic opportunity to the north, across 90 miles of ocean. The free, universal education system, so prized by Cubans, teaches the party line. Socialist slogans are everywhere. Billboards, the likes of which would be prime advertising space in a capitalist society, tout the nation's heroes and the value of being like them - defenders of the revolution.

Signs and statues of martyrs, including Che Guevara and José Martí, are common. You'll rarely see images of Fidel on posters or billboards. He objects to a "cult of personality," we're told. That's what it is, though.

Anita Snow, chief of The Associated Press' Cuba bureau, told us, "Nobody has that guy's charisma. He believes what he's doing is absolutely correct … moral and right."

And though Cubans aspire for a better life, it seems likely that most of them would fight to the death to defend "Daddy Fidel," their land - and the revolution.

Who knows what will happen when Fidel dies? Fidel is 77 and in relatively good health.

"Of course there will be differences (in the government)," National Assembly President Ricardo Alarcón told the American journalists during a meeting in a Havana hotel. "You cannot substitute one human being for another. There would be differences in style. The idea that it would be linked to a change in our society is arbitrary. … It is not the person. The person is replaceable."

The National Assembly of the People's Power is the equivalent of a national parliament or congress, although it meets only twice a year for a short period of time. The Assembly elects and delegates powers to the Council of State and its president, who is the head of state (Fidel Castro).

According to the Cuban Foreign Ministry, "All representative bodies of state power are elected and replaceable."

U.S. government officials laugh when asked about democracy in Cuba. The U.S. has called for regime change since Fidel assumed the reins of power in 1959 and nationalized private and foreign holdings throughout the island.

Cubans see the U.S. as the same threat to their country as when it instigated the Bay of Pigs invasion. Cuban officials say that the U.S. government encourages "terrorist" operations planned by Cuban exiles based in Miami as part of its efforts to force Castro from power.

"We want to live in peace with the United States, but we want respect for our sovereignty," Rafael Dausá told the U.S. journalists during a visit to the Cuban Foreign Ministry office in Havana. Dausá is director of the ministry's North American Division.

He said that normalized relations between the U.S. and Cuba would allow cooperation on commerce, on combating illegal drugs and illegal immigration, and on the international fight against terrorism.

The U.S., Dausá said, must "respect Cuba's right to be different. … Unfortunately all we get from the U.S. are new restrictions. … I consider the government of the United States wants to destroy Cuba."

Smiling at the understatement, Alarcón told the journalists, "The situation between our two countries has not been particularly smooth for a long time."

He is considered by some Cuba watchers to be a possible moderate successor to Castro.

"It's very important, getting to know each other better," Alarcón said.

In a speech last year in Miami, James Cason, head of the U.S. Interests Section in Havana, said, "For too long, Fidel Castro has obscured Cuba's problems in the veil of national sovereignty and his fractious relationship with the United States. … Change will come to Cuba; in fact, it is already under way. Cubans will decide how the Cuba of tomorrow takes shape. … I can pledge that the United States stands ready to assist the Cuban people when asked."