Brief during political campaign the pits, slow unfortunately (7-4)
I believe the answer is:
whistle stop
'brief during political campaign' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'the pits slow unfortunately' is the wordplay.
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'the'+'pits'+'slow'='thepitsslow'
'thepitsslow' with letters rearranged gives 'WHISTLE-STOP'.
Can you help me to learn more?
(Other definitions for whistle stop that I've seen before include "Fast and with only brief pauses" , "Like hectic tour" , "brief tour" , "Description of a politician's brief appearance" , "Pause to speak" .)