Paul W. answered 03/29/20
Dedicated to Achieving Student Success in History, Government, Culture
During his long and brutal rule as dictator of the Dominican Republic, Trujillo exploited, exacerbated, and institutionalized ant-Haitian attitudes among Dominicans, anti-Haitian attitudes that amounted to discrimination and even violence directed towards people with darker skin and African features.
It's important to understand that Trujillo did not create the anti-Haitian feelings of most Dominicans. These attitudes originate in the origins of the the two countries that share the island of Hispaniola - Haiti located in western portion of the island and the the Dominican Republic occupying the western portion of the island - and how these two countries interacted. The Dominican Republic was originally a Spanish colony containing a mixed population of the original Native American inhabitants, Europeans from Spain, and slaves from Africa. While the Spanish rulers enforced a racial hierarchy, the different peoples of their colony intermarried, producing a mixture of 'races'. By contrast, Haiti was originally French colony. Although intermarriage took place in the French colony of Haiti, during the revolution that resulted in Haitian independence from French rule, all of the people of European descent either fled or were killed, leaving a population that was either entirely of African descent or 'mulatto' (mixed African-European descent).
During the 19th century, the independent nation-state of Haiti launched frequent invasions of neighboring Dominican Republic, actually ruling over the Dominican Republic from 1822 to 1844. As a result, not only did the people of the Dominican Republic view the people of Haiti as different from them, but they viewed the Haitians as their natural enemies, having had to fight against Haitian invaders time and time again.
When Trujillo became the ruler of the Dominican Republic he exploited the anti-Haitian feelings - the equivalent of anti-Black bigotry - using the dislike of Haitians as means of creating a scapegoat towards which the Dominican people could direct their anger (and, thus, diverting their anger from Trujillo himself). In particular, Trujillo blamed many of the country's problems on the thousands of illegal Haitian immigrants who lived in the Dominican Republic. In October, 1937, Trujillo ordered his army to attack Haitian communities located along the Dominican-Haitian border, resulting the massacre of thousands of defenseless Haitians - men, women, and children.
Throughout his long reign, which only ended with his assassination in 1961, Trujillo promoted discrimination against Haitians living in the Dominican Republic and instituted the ejection by force of these people, returning them to Haiti.