Clothes worn by power party bosses (3,4)

'bosses' is the definition.
(a top dog is a powerful person)

'clothes worn by power party' is the wordplay.
'clothes' becomes 'togs' ('tog' can be a synonym of 'clothe').
'worn by' is an insertion indicator (I've seen this in other clues).
'power' becomes 'p'.
'party' becomes 'do' (do is a kind of party).
'p'+'do'='pdo'
'togs' enclosing 'pdo' is 'TOP DOGS'.