Also called some bipartisan wonks back (5,2)

'also called' is the definition.
(also known as)

'some bipartisan wonks back' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'back' says the letters should be written in reverse.
'sanwonk' can be found hidden inside 'bipartisan wonks'.
'sanwonk' written backwards gives 'KNOWN AS'.