Elected essentially dangerous, vacuous President? Hopeless! (5)
I believe the answer is:
inept
'hopeless' is the definition.
(I've seen this before)
'elected essentially dangerous vacuous president?' is the wordplay.
'elected' becomes 'in' (in government).
'essentially' says to take the centre.
'vacuous' says to hollow out the word (remove centre letters).
The middle of 'dangerous' is 'e'.
'president' with its centre removed is 'pt'.
'in'+'e'+'pt'='INEPT'
(Other definitions for inept that I've seen before include "Absurd or unskilful" , "Lacking skill" , "Ham-fisted" , "Lousy" , "Amateurish" .)