Answer:Senator Obama's choice to begin his speech with an explanation of his family members' background reflects the purpose of his speech in several ways: - Establishing Common Ground: By sharing his personal story, he connects with the audience on a human level. This builds trust and empathy, creating a sense of shared experience and understanding. This is especially important in a political context where differences can be emphasized.- Highlighting the American Dream: His family's journey, from humble beginnings to achieving success, embodies the classic American Dream narrative. This resonates with a core value of the American identity and positions him as someone who understands and values those aspirations.- Emphasizing Inclusivity: By highlighting his diverse heritage, he implicitly advocates for inclusivity and diversity. This sets the stage for his broader message about unity and shared responsibility.- Framing His Message: The personal narrative serves as a foundation for his political message. It demonstrates that his values and beliefs are rooted in real-life experiences, making them more relatable and authentic. In essence, the personal anecdote serves as a powerful tool to establish his credibility, connect with the audience, and set the stage for his broader message about hope, change, and the future of America.