It's futile ignoring the odds to indulge a Conservative (8)
I believe the answer is:
nugatory
'it's futile' is the definition.
(thesaurus)
'ignoring the odds to indulge a conservative' is the wordplay.
'ignoring the odds' indicates alternate letters (letters in odd-numbered positions are removed).
'conservative' becomes 'tory' (I've seen this before).
The alternating letters of 'indulge' are 'nug'.
'nug'+'a'+'tory'='NUGATORY'
(Other definitions for nugatory that I've seen before include "Insignificant or trivial" , "Worthless or of no real value" , "Futile, of no value" , "Triflingly unimportant" , "Any grout (anag) - trifling" .)