This poem is actually more famous for its use in naming the famous play written by Lorraine Hansberry, A Raisin in the Sun. It is based around the central question of what happens to a dream that is never achieved. The various images that Hughes uses to compare this deferred dream suggests the pain and unhappiness that these kind of dreams cause: he variously compares it to a dried raisin in the sun, a festering sore, a rotten piece of meat, before suggesting that it might sag "like a heavy load." Hughes reserves his most shocking theory though for the final line of the poem, where he asks another question:
Or does it explode?
Given the context in which Hughes was writing, when so many African-Americans were desperately hoping for a brighter future, and had to face a constant deferral of their dreams, this possibility, placed as it is at the end of the poem in a line of its own, is most disturbing. The question mark at the end raises the possibility of an "explosion" amongst those who are not able to achieve their dreams, suggesting violence and suffering of some description. The poem therefore charts the different responses people might have to never being able to achieve their dreams, implicitly arguing that achieving dreams is something vital to the human condition, and stating that a failure to achieve those dreams can be incredibly negative.