US party member (8)
I believe the answer is:
democrat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">us party member</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 democrat that I've seen before include "US politician" , "One who believes in government by the whole people" , "US political party supporter" , "Republican's US rival" , "Populist" .)