Clue: Eccentric part for outspoken drag queen crusader (10)
Answer: CAMPAIGNER
Explanation: Definition: crusader
**CAM**="Eccentric part"*; plus **PAIGN** which sounds like 'pain'="outspoken drag"**; plus **ER**="queen" 
*Eccentric meaning set off-centre, and a cam is off-centre or irregularly shaped around a rotating shaft, transferring rotational movement to another part of the mechanism
 **'drag' as in something tedious or tiresome to deal with