Fake American politician runs over (5)
I believe the answer is:
repro
'fake american' is the definition.
(US term for a reproduction or fake)
'politician runs over' is the wordplay.
'politician' becomes 'rep' (rep is a kind of politician).
'runs' becomes 'r' (cricket abbreviation).
'over' becomes 'o' (cricket abbreviation).
'rep'+'r'+'o'='REPRO'
(Other definitions for repro that I've seen before include "piece of furniture?" , "Copying (of a document)" , "unoriginal style of furniture" , "Type of furniture" , "Roper (anag.)" .)