No, I don't think the G.O.P. will dump Donald Trump as a candidate. Too many people in the party love the guy and you can't alienate that many folks by taking away the guy they voted for and replacing him with someone he beat or who didn't enter the fray at all. If Trump gets out, it will have to be because someone offered him enough financial reward.
Which is not to say there aren't Republicans who'd like to see him go away. William Saletan lists ten vile things Donald has done just since the convention. How many more will it take before prominent Republicans start rescinding their endorsements or at least distancing himself from their party's nominee?