This is partly because most pundits are terrible at this kind of analysis, prone to groupthink, blind to their own prejudices, easily swayed by the most blatant of manipulative ploys and generally not nearly as smart as they think they are. Mainly though, the topic usually isn't worth that much attention. Compared to questions of policies and competence, issues of character and psychological make-up almost always fade into triviality.
Until recently, the only notable exception was Nixon, and even there, I'm not sure real time analysis would have been that productive. It took a while for the full story to come out. With Trump, though, the emotional issues are so close to the surface and are so obviously driving the process that to ignore them is to omit an essential part of the story..
For example, with a normal campaign, whether or not a candidate is having fun is a secondary, if not tertiary, issue. It's true that the best politicians tend to love campaigning, but they don't make tactical, let alone strategic, decisions based on whether they're enjoying themselves.
With Trump, though, it is entirely appropriate to ask what will happen to the presumptive GOP nominee when the process goes from non-stop fun to no fun at all. I was planning to write a post on this but Gawker's Ashley Feinberg got there first and hit most of the points I wanted to cover.
Remember, Trump had a blast during the primaries. Back then, he was free to spew any sort of nonsense he wanted. And not only did no one question him too seriously, but as his discourse became increasingly unhinged and racist, his poll numbers rose in kind. The more his poll numbers shot up, the more media attention he got. And for Trump, there is no purer joy. If Donald Trump is able to buy his way into heaven, it’s just going to be him reliving the 2016 primaries every day for the rest of eternity.
Now, though, the Democrats are just about done squabbling, Republicans are out of distractions, and the cold, sobering reality of what our nation has wrought is finally settling in. Now that the fun is winding down, the small-handed prince of our country’s most base anxieties is going to start looking for a way out. He’s already laying the groundwork, saying on Fox & Friends that “it would be nice to have full support from people that are in office, full verbal support. With all of that being said, I may go a different route if things don’t happen.”
Feinberg then walks through the various scenarios for withdrawal. All of them are long shots, but at this point I'm not ruling anything out.