This literary term is called an "epiphany". They are quite common and have been occurring in literature as far back as ancient Greece. A writer famous for his characters' epiphanies is James Joyce for example.
Answer:
Whitman had written a long poem and some of the readers might feel bored reading it, so he used this device to give some energy to it. Since anaphora is repetition, it keeps on getting in the mind of the readers thus giving emphasis to the ideas he expresses.
I believe your answer is 1. character versus society. Hope this helped!
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~Steve
