Salon's Heather Digby Patron summarizes the consensus opinion that the Republican party is responsible for his "creation"—but also suggests that it still doesn't understand him and enjoys little prospect of stopping him.
The assumption among the establishment types is that if only Cruz, Kasich and Carson would get out of the way, all those voters would go to Rubio and they could finally knock out Trump and carry on with the plan. Unfortunately, even if they were able to finally get Rubio a free lane in which to run, there's no guarantee that he would be the beneficiary of all those freed up votes. That's because Trump draws from every demographic.
Trump isn't consistently right-wing, after all. In practice, he's a mix of centrist vacillations and a few extremist stunt positions. He panders to an angry middle of people with inane and self-absorbed media-fed beliefs about politics they never cared to understand in the first place: "it doesn't matter what he says, as long as he delivers his lines with that big swinging attitude of his."
Think of tired boomers drifting into shitty retirements and angry adolescents drifting into shitty adulthoods, and you get Trump. Say another Hitler joke. And another. And another for the road.