President that was the beginning of the end (5)
I believe the answer is:
trump
'president that was' is the definition.
'trump' can be an answer for 'president' (Donald Trump). I'm not certain of the rest of the definition.
'beginning of the end' is the wordplay.
'beginning of' says to take the initial letters.
'end' becomes 'rump' (I can't explain this - if you can you should believe this answer much more).
The initial letter of 'the' is 't'.
't'+'rump'='TRUMP'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for trump that I've seen before include "High card" , "It may be the last you hear" , "club perhaps" , "US President" , "High-ranking card" .)