In the Castro brothers’ Cuba, Barack Obama looked like a time traveler returned from the future — one of those who, in science fiction, are transported back in time by a time machine just like the one envisaged by Ray Bradbury and many others.

On our television screens we saw the U.S. president plow through the ancient streets of Havana in his armored limousine known as “The Beast.” This is a limousine made of a steel-titanium alloy designed to resist the impact of a rocket launcher, and which is armed with its own rocket launcher, night vision apparatus and a million other gadgets. Cadillac One moved through the beat-up Soviet-era Ladas and the 1950s Buicks as if it had come straight out of a film set in the distant future.

Naturally, the limousine and the rest of the presidential entourage fascinated the watching Cubans. At times it seemed as if Obama wasn’t only from a different country, but from a different time entirely. The biggest temporal discrepancy did not, however, come by way of the evident technological contrast between the world’s strongest power and a developing country — Obama and his family also seemed like futuristic time travelers for a much simpler reason: the color of their skin.

After half a century of revolution and enormous sacrifices of freedom in the name of equality, black and mixed-race people, who represent a majority of the country’s population, remain far from power. Although more than half the population are black or mixed-race, only one-third of the National Assembly and one-fifth of the leaders in the Politburo are of this same ethnic origin. The majority of the communist leadership — the Castros first and foremost — are white. Prospects for the near future appear bleak when you consider that the heir-apparent to the revolution, Miguel Diaz-Canel, is even whiter than his predecessors.

In the United States, African-Americans make up 13 percent of the population — a minority which still suffers from discrimination and who are finding themselves left behind by society. However, American democracy has allowed a member of this minority to become president of this “reactionary” country, while on the revolutionary island, where a majority of people are black or mixed-race, it seems unlikely that someone from either of these groups will replace the Castros.

Speaking in the Great Theatre of Havana Alicia Alonso, the U.S. president subtly highlighted this difference when he said, “Now, there are still some tough fights. It isn’t always pretty, the process of democracy. It's often frustrating. You can see that in the election going on back home. But just stop and consider this fact about the American campaign that's taking place right now. You had two Cuban Americans in the Republican Party, running against the legacy of a black man who is president, while arguing that they’re the best person to beat the Democratic nominee who will either be a woman or a Democratic Socialist. Who would have believed that back in 1959?"

Few people in the racially segregated 1950s America would have predicted that members of those minorities would now be able to reach power. At the same time, very few, including those who believed in the egalitarian ideals of the revolution, would have predicted that after 56 years, the possibility of a black person, a person of mixed-race or a woman gaining access to power in Cuba would remain so remote. Who could have predicted that the hunger for radical change of that young revolution was going to stagnate and morph into this aging resistance to nothing but change?

In Ray Bradbury’s “A Sound of Thunder,” a time traveler journeys back to the Jurassic period. While there, a Tyrannosaurus rex scares the traveler, who steps off the anti-gravity walkway that prevents his feet from touching the jungle floor. When he returns to the future, the traveler discovers that great changes have taken place, some of them political. Searching for an explanation, he examines the sole of his boot and, to his horror, discovers a crushed Jurassic butterfly. A small change in the past can have huge effects on the future.

The gradual lifting of the absurd trade embargo and the subsequent increase in contact between the people of Cuba and of the U.S. will certainly bear fruit. Without doubt, the effects of these changes will be more long-lasting than the conciliatory words of Obama that will shortly be forced from the memories of the people of Cuba by the regime’s oppressive propaganda.

However, it is likely that another memory of this visit will be harder for the regime to erase, given that it doesn’t solely consist of words. The image of a mixed-race U.S. president and his African-American family will doubtlessly provoke a subtle and long-lasting butterfly effect on the island. That one detail — the color of the president’s skin — could help to change the color of Cuba’s future.