The previous poster's comments are all very good, but as I understand harley08's original post, the question hasn't yet been answered.
The final line of Langston Hughes' short poem (sometimes titled "Harlem") reads: "Or does it explode?" Many of the lines before that last line contain similes: "like a syrupy sweet," "like a heavy load," and so on. So this final line, too, could be completed as a simile, but what should the explosion be compared to?
"Or does it explode like a supernova?"
"Or does it explode like a ticking bomb?"
"Or does it explode like a can of soda in the freezer?"
There's no right answer, of course! What are some other possible ways to complete that final line?
Simile by simile, Hughes shows different attitudes, including violent protest, thatblacks might possibly take toward the long deferral of their dream of equality. Readers might be asked what meaning they find in each comparison. Also worth noting are the strong, largely unpleasant verbs used to characterize the types of decay caused by deferring the dream—dry up, fester, run, stink, crust and sugar over,and sags. No wonder an explosion is likely to follow. Hughes’s poem supplied the title for Lorraine Hansberry’s long-running Broadway play, A Raisin in the Sun (1958), in which the Youngers, a family descended from five generations of slaves, come to a Chicago ghetto in hopes of fulfilling their dream.
If the poem had ended with a simile instead of a metaphor, the pwerfulness of the last line would not be dampened but tempered with a line such as:
Or, like an explosion?