Moderates will vote down-ballot but not for Trump. Trump's supporters will vote for him now and no "establishment" Republicans.
It's a perfect storm of failure landing on the GOP. Savor it.
First, a close win is never better than a big win.
Second, many Trumpsters are furious at the GOPers disendorsing him.
I can;t see any scenario where a close victory represents a better result.
He has attracted enough attention to his total failure as a scam artist business man that it appears to be making him more of a loser. Because of that he has worked hard to screw everyone including the rnc. He will be responsible for splitting the vote. The republican vote will have a hard time or never be the same. He is a scorched ground artist who will destroy anyone who he feels offended him. I am not going to say it will be the total destruction of the rnc. But he has been successful at driving deep wedges in the repub party it may take years to heal if it can. Listen to the repubs who have come out and endorsed Hillary. Listen to the deep red repubs who will not endorse dipshit, they will probably not even vote for him. They may not vote for Hillary, but they won't vote for him. I really think there will be average repub voters who will do the same. Not vote for Hillary, but also not vote for dipshit. He is at 70% for repub voters, that is piss poor. Nation wide presidential polls seem to bare it out. It also seems a larger amount of "undecided" and maybe some repub voters are going with Hillary.
as a democratic candidate you hang trump around the neck of your republican opponent....the republican opponent is screwed no matter what he does...if he condemns trump, trump zealots will not vote at all or vote for the democrat...if the republican opponent embraces trump then he drives moderate republicans AND woman to the democratic candidate or they dont vote at all....both scenarios and subsets are a win-win for democrats....