Think of the speaker as an interested and horrified third party. We're not coming at this from anyone's specific point of view, unless you want to count the poet herself. But there is no "I" in this poem – most of it is in the third person.
So then who's talking? We might be able to imagine the speaker as a kind of poetic historian – someone who has just found out these horrible facts about the history of Haitians in the Dominican Republic, and wants to make sure that we know about it. The speaker is concerned with issues of hate, especially when it's race-related, and since stumbling upon this piece of history, has not been able to let it go. Thus the repetitive insistence – since the story seems almost too bizarre to be true, the speaker must convince us that it is, in fact, true, and that it bears thinking about. Sometimes the only way to get your point across is to reiterate it multiple times. So that's one way to think about where the speaker is coming from.