Are Trump's platform and ideas the reason he is losing, or does it have more to do with his personal character and shortcomings? If it's the latter, they may be able to take his outline and succeed with it. Remember how close the race was before the first debate?
It really does have to do with his persona.
One charge against Trump that is true is that he can't put aside personal slights and attacks. He sabotages himself in this regard. Saying "Such a nasty woman!" in the middle of the debate last night is an example. Hillary IS nasty; she's one of the most ruthless politicians in either party to ever run for President. But you don't SAY this; you let people come to conclude that on their own. Trump doesn't get this, and I'm resigned to the fact that he can't do anything meaningful about it at this late date.
This is compounded by the fact that Trump really isn't a good public speaker and isn't real quick on his feet. Hillary gave him all sorts of opportunities to slam her in the debate last night, and he just couldn't seem to do it. He couldn't slip in the best zinger at the best time, and it hurt him. Ruthless Hillary (that's her REAL nickname, IMO) knows how to zing Trump, and Trump let her get away when it came to Bill, to "Deplorables" and to the Clinton Foundation (where she DOES NOT WANT TO GO).
I listened to Don Trump (Jr.) after the debate. He's fluid, well spoken, and all I could think of was that if Don, rather than The Donald, was debating Hillary, he'd have turned her into mincemeat. But Don isn't the candidate; his Dad is. Don Trump knows how to stay on message better than his Dad. Perhaps the wrong Donald Trump is the Presidential nominee. He'd have done a better job in the General Election of getting the Trump points across of Immigration, Trade, and Foreign Policy that brought about a revolution in the GOP and still have the potential to bring about a revolution in General Election politics.