Music genre influential on election night? (5)
I believe the answer is:
swing
I believe this is a double definition.
'music genre' is the first definition.
'influential on election night?' is the second definition.
(as in swing voters)
(Other definitions for swing that I've seen before include "Shift opinions; hang" , "in the park?" , "style of music" , "Type of big-band jazz" , "Move from side to side" .)