A thought registers with these people (9)

I believe the answer is:

idealists

'these people' is the definition.
(idealist is a kind of person)

'a thought registers' is the wordplay.
'a thought' becomes 'idea' (idea is a kind of thought).
'registers' becomes 'lists' (listing is a kind of registering).
'idea'+'lists'='IDEALISTS'

'with' is the link.

(Another definition for idealists that I've seen is " visionaries".)

I've seen this clue in The Telegraph.

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