Unusual case of Washingtonian with positive opinions (10)

'opinions' is the definition.
The definition and answer can be both related to thinking as well as being plural nouns.
Perhaps there's an association between them I don't understand?

'unusual case of washingtonian with positive' is the wordplay.
'unusual' is an anagram indicator.
'case of' suggests removing the centre (outsides of).
'with' is a charade indicator (letters next to each other).
'washingtonian' with its centre taken out is 'wn'.
'wn' after 'positive' is 'positivewn'.
'positivewn' is an anagram of 'VIEWPOINTS'.

Can you help me to learn more?