Thanks - and yes, he is Mobutu! The clue leads to ?o?u?o and I think those letters are all correct. The critical 'o (at the end) comes from ...
Admit being involved in 'awful turd' Corbyn's ultimate decline (8)
I got that to be Downturn, decline - Own, admit + the 'n' at the end of 'Corbyn' and 'turd'.