The others weren't compelling, but at least most of them weren't completely nuts.
Sure, the Republican primary electorate found Trump compelling, and that's why they won. And that's what scares me. I don't think they necessarily should have found any of the others compelling (what an awful field of candidates, I mean, seriously, what happened there?) but that's beside the point.
If by "loses" you mean "loses the general election", that could be a bit problematic.
In 2000, Bush mainly kept his mouth shut. But Gore's campaign manager made a series of public statements along the lines of "Gore has clearly won, and if this goes to Bush it's a travesty of the election." That didn't help heal or unite the country after the election; arguably, the division has remained ever since.
Trump could do the same thing, but do it much more loudly, bombastically, and in a more attention-grabbing way. The only prevention would be for him to lose so strongly that nobody listens, and everyone writes it off as the whining of a bitter self-deluded loser.
Sure, the Republican primary electorate found Trump compelling, and that's why they won. And that's what scares me. I don't think they necessarily should have found any of the others compelling (what an awful field of candidates, I mean, seriously, what happened there?) but that's beside the point.