In "The Haunted Oak," Dunbar identifies important white men who join the nightriders in perpetrating a lynching. Which institutions does Dunbar attack through these identifications?

In the poem, Dunbar attacks through these identifications to the legal institution, represented by a judge, who is described wearing a black mask, also refers to the medical institution, as it describes a doctor wearing a white mask; and finally attacks the institution of the Church, because Dunbar describes a minister, with his eldest son. All this is clearly the way to expose how every part of American and white society is racist, and engage both the professionals, the high church members, as well as the representatives of the judiciary power, all involved in the horrible act of lynching a old african-american man.