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' indicates the central letters.
'vacuous' says to hollow out the word (remove centre letters).
The middle letter of 'dangerous' is 'e'.
'president' with its middle taken out 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" .)