Final answer:
McCarthy mentions John Service and Gustave Duran as examples of guilt by association and to illustrate the unfounded accusations and hysteria of the McCarthy era.
Step-by-step explanation:
McCarthy likely mentions John Service and Gustave Duran in paragraphs 12-14 to illustrate the focus on accusations over evidence that characterized the tactics used during the McCarthy era. This reference to Service and Duran serves as an example of guilt by association, a common practice at the time, which often led to the persecution of individuals based on their perceived affiliations, rather than any concrete proof of wrongdoing. Such references help to highlight the hysteria and unfounded claims that were rampant during the period, and they provide a historical context to the fear and misdirection used by McCarthy and his followers.