I test aggression displayed by those who promote division (15)

I believe the answer is:

segregationists

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'by those who promote division' is the definition.
I can't tell whether this definition defines the answer.

'i test aggression displayed' is the wordplay.
'displayed' indicates an anagram (letters displayed in another way).
'i'+'test'+'aggression'='itestaggression'
'itestaggression' with letters rearranged gives 'SEGREGATIONISTS'.

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I've seen this clue in The Irish Times.

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