Answer:
anaphora.
Step-by-step explanation:
Anaphora is a technique in rhetoric where a word or phrase is repeated at the beginning of multiple clauses or sentences. It is used to create emphasis, reinforce a point, and add rhythm or musicality to the speech or written piece. In this case, Obama's repetition of "we" at the beginning of each clause helps to emphasize collective action and unity by repeatedly highlighting the inclusive pronoun "we."