Mafia kingpin
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mafia kingpin</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for capo that I've seen before include "crime boss" , "something to grip neck tightly" , "Mafia boss" , "Movable bridge" , "Mafia chief?" .)