Cross-party members caught in the middle of voters (8)
I believe the answer is:
traverse
'cross' is the definition.
('traverse' can be a synonym of 'cross')
'party members caught in the middle of voters' is the wordplay.
'party members' becomes 'ravers'.
'caught in' is an insertion indicator.
'the middle of' indicates the central letters.
The middle letters of 'voters' are 'te'.
'ravers' placed inside 'te' is 'TRAVERSE'.
(Other definitions for traverse that I've seen before include "Move across" , "Extend or bridge across" , "get across" , "Cross sideways" , "Travel across or pass over" .)