You are spot on with his plagiarism but you are forgetting that Trump has really lowered the bar as to what we expect from a President.
Only time will tell if his previous unsuccessful bids will hurt him. Will those voters who are to young to remember that even care?
Whoever the candidate ends up being if they try and take the high road in the debates they will get stomped on by Trump. They need to get as personal, nasty and vindictive as Trump is. Which leads me back to the fact Trump is lowering the bar. This is not how I want our elected representatives to act, on either side.