Twisted delegate made phone call up (7)
I believe the answer is:
gnarled
'twisted' is the definition.
(gnarling is a kind of twisting)
'delegate made phone call up' is the wordplay.
'delegate' becomes 'del' (political abbreviation).
'made phone call' becomes 'rang'.
'up' is a reversal indicator (in down clue: letters go upwards).
'del'+'rang'='delrang'
'delrang' reversed gives 'GNARLED'.
(Other definitions for gnarled that I've seen before include "Old, twisted, and weathered" , "Knobbly and twisted (of wood)" , "Knotted, twisted (tree)" , "Knotty" , "Covered with knobs or knots, tree say" .)