can anyone think of other examples of this phenomenon?

How about "Marxist", after Karl Marx, or

Luddite "after Ned Ludd, an English laborer who was supposed to have destroyed weaving machinery around 1779."
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re is there a specific rhetorical term for the metaphorical borrowing of a noun referring to a group of people for use in describing a person who shares that group's salient qualities?

How about ...

eponym

"A person whose name is or is thought to be the source of the name of something, such as a city, country, or era. For example, Romulus is the eponym of Rome."

[French éponyme, from Greek epnumos, named after : epi-, epi- + onoma, onuma, name; see n-men- in Indo-European Roots.]

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