anaphora is used here. anaphora is the repetition of a word or phrase at the beginning of a series for emphasis, and in this excerpt, the author/speaker is using "let us not" repeatedly to emphasize that they do not want to discuss certain heavy topics plaguing the country.
a common example would be martin luther king jr.'s i have a dream speech. he repeated the words "i have a dream" over and over to emphasize his beliefs.
