Nothing right about politician's blast (5)
I believe the answer is:
tromp
'blast' is the definition.
(I have seen 'A blast' mean 'tromp' so perhaps 'blast' could also mean 'tromp')
'nothing right about politician's' is the wordplay.
'nothing' becomes 'O' (O resembles 0).
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'about' says the letters should be written backwards.
'politician' becomes 'MP' (Member of Parliament).
'o'+'rt'='ort'
'ort' reversed gives 'tro'.
'tro'+'mp'='TROMP'
(Another definition for tromp that I've seen is " A blast".)