The fact that there are no good choices of political leaders is just a maturation of the political climate and 
distaste for all politicians that they themselves have created. Instead of louring new smart intelligent women and men we get egotistical, radical, dim witted and otherwise unemployable civil servants. No one with a sense of morals and intelligence wants the slimy job. They can make a better life for themselves by using their talents elsewhere. So you're left with people who can only ride in limos because of government funds, not their skillset and earnings.
I believe it was John Crosby who said it's the 90% of politicians who give the other 10% a bad name. Today I think they've achieved a goal of 100%. 
That explains "Why Trump"