Race over to upset journalist getting entrenched (4-6)
I believe the answer is:
deep-seated
'entrenched' is the definition.
(thesaurus)
'race over to upset journalist' is the wordplay.
'race' becomes 'speed' ('speed' can be a synonym of 'race'**).
'over' shows that the letters should be reversed in order.
'to upset' becomes 'eat' (eat can mean to upset or distress).
'journalist' becomes 'ed' (short for editor).
'speed' written backwards gives 'deeps'.
'deeps'+'eat'+'ed'='DEEP-SEATED'
'getting' is the link.
(Other definitions for deep-seated that I've seen before include "Firmly-established" , "Firmly fixed" .)