Southeastern Maine has a fairly large black population that is growing fairly quickly, particularly in the suburbs around Portland. Portland itself is a pretty accepting city. Haven't heard of a single unwarranted police shooting in the state. Might have some trouble in the more rural communities, but any outsider does- they tend to be places where everyone knows everyone, populations where the same families have lived in the area for centuries. Bangor might not be as bad, as would some of the other small cities, but if you go rural, be prepared for some barriers.