The reasoning the speaker uses to show how her evidence supports her claim can best be summarized as follows:
She talks about the values her mother raised her by and now she shares those values with Joe Biden.
In her speech, Kamala Harris reflects on the lessons she learned from her mother, emphasizing service to others and the importance of community. By linking her personal upbringing to her vision for the country and aligning it with Joe Biden's beliefs, she underscores her commitment to these values as she accepts the nomination.