How does the comparison of the situation to the "secret heart of
America itself" reflect the historical context of the passage?
It shows that people were not ready to hear what he had to say.

It emphasizes the idea that the secretive actions of a few can harm a
great number of people.
It highlights the importance of being aware of how people think and feel
about a subject.
It reinforces the idea that the issue was emotionally significant to the
country.