Notice sticker up in office electioneer vacated, supporting Clinton (4,6)
I believe the answer is:
bill poster
'notice sticker up' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'office electioneer vacated supporting clinton' is the wordplay.
'office' becomes 'post' (both can mean a position or job).
'vacated' suggests removing the centre (internal letters vacate the word).
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'clinton' becomes 'Bill' (US president Bill Clinton).
'electioneer' with its middle taken out is 'er'.
'post'+'er'='poster'
'poster' put after 'bill' is 'BILL-POSTER'.
'in' is the link.
Can you help me to learn more?
(Other definitions for bill poster that I've seen before include "one who mails accounts" , "He sticks up for his employer" .)