Three objective reasons why Trump should not be president:
1. His economic plan is a twice-proven failure. It's the old trickle-down theory that failed for Reagan and for George W. Bush. Experts estimate that it would cost the treasury $15 trillion over 10 years.
2. He denies global warming. It's bad enough that he would stop and rollback all efforts that have been made to curtail that trend, but, worse, it shows that he puts his opinion ahead of the facts.
That's what George W. Bush did when warned of a terrorist attack. He ignored it because he knew that Iraq was the real threat. Then came 9/11.
3. He is not astute. During one of the debates, when Jeb Bush said that his brother had kept us safe, Trump just nodded dumbly. It wasn't until the next day, when several pundits brought up 9/11, that he joined the chorus. And he claims to be a great negotiator.
He has demonstrated a thin skin and a whiny reaction to adversaries -- an almost adolescent behavior that further belies this claim.