Power to influence (8)
I believe the answer is:
leverage
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">power to influence</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for leverage that I've seen before include "Power of achievement; (US) gearing" , "Power to influence" , "can achieve power" , "What crowbar provides" , "Power -- advantage" .)