Politically extreme (7)
I believe the answer is:
radical
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">politically extreme</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for radical that I've seen before include "Progressive - car dial (anag)" , "(One) favouring fundamental changes" , "One seeking root and branch reform" , "Deep" , "Militant" .)