Mediocre POTUS prancing around in weskit and breeches? (6,7)

I believe the answer is:

period costume

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'in weskit and breeches?' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'mediocre potus prancing' is the wordplay.
'prancing' is an anagram indicator.
'mediocre'+'potus'='mediocrepotus'
'mediocrepotus' is an anagram of 'PERIOD COSTUME'.

'around' is the link.

Can you help me to learn more?

(Another definition for period costume that I've seen is " outfits from the year dot?".)

I've seen this clue in The Telegraph.

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