Influential student group changing sides finally (7)

I believe the answer is:

seminal

'influential' is the definition.
(seminal can mean important or influential)

I cannot understand how the remainder of the clue works.

(Other definitions for seminal that I've seen before include "Giving rise to new developments by menials" , "Generating new developments for menials" , "Of beginnings or early developments" , "Highly original" , "Menials (anag) - creative" .)

I've seen this clue in The Times.

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