Nurse a politician briefly, one in upper house (7)
I believe the answer is:
senator
'one in upper house' is the definition.
(the senate is the upper house of US politics)
'nurse a politician briefly' is the wordplay.
'nurse' becomes 'sen' (abbreviation for Senior Enrolled Nurse).
'politician' becomes 'tory' (term for a Conservative Party politician).
'briefly' means to remove the last letter.
'tory' with its final letter removed is 'tor'.
'sen'+'a'+'tor'='SENATOR'
(Other definitions for senator that I've seen before include "US representative" , "Legislator -- treason (anag)" , "Clinton, perhaps" , "Statesman -- treason (anag)" , "US politician" .)