The line from Daniel Dae Kim's statement that serves as an example of metaphor is:
Line 1: "We cannot simply be painted with the broad brush of assumption that the most successful of us represent the totality of us."
In this line, "painted with the broad brush of assumption" is a metaphor, as it compares the act of making generalizations about a group of people to the act of painting, suggesting a lack of nuance or consideration for individual differences.