Clue: Defence given by ol' prince, closet racist? (9,11,4,3)
Answer: POLITICAL CORRECTNESS GONE MAD
Explanation: Definition: Defence
POLITICAL CORRECTNESS is an anagram (GONE MAD) of OL' PRINCE, CLOSET RACIST – and sort of &lit, referring perhaps to Prince Philip's notoriously un-PC remarks. 
*288 corrected to 28 in published version