Final answer:
Robert Martin would describe Lewis as a hypocrite.
Step-by-step explanation:
In this scenario, Robert Martin would describe Lewis as a hypocrite.
Despite saying terrible things about African-Americans when he is with his Mexican-American friends, Lewis smiles and says hello when he encounters a group of African-Americans on the street. This contradiction between his actions and words suggests that Lewis is being hypocritical.
This behavior could be a reflection of Lewis holding prejudiced beliefs but still maintaining a friendly facade when faced with actual individuals from the group he speaks negatively about.