The best way to understand Donald Trump, in my opinion, is to think about Ron Paul's problems in 2011.
Why did the media smirk whenever Ron Paul tried to take the stage, even though the crowd went wild?
Ever since the Southern Strategy was established, Republicans have been promising their constituencies Trumps and delivering something else instead. There was no way on earth this three-card monte trick was going to last forever.
Yet in 2011, Ron Paul won huge crowds, and when the media spoke of him, they smirked. They didn't see the impending doom of the Southern Strategy. They saw a joke. Why?
Because the media class controlled what could be discussed, and they ruled Paul out. He campaigned without their approval, and they thought that was hilarious. Television had controlled politics since the Nixon-Kennedy debates, and the idea that you could win without media support was ridiculous to the people who ran the media.
Those debates were a pivotal moment in American politics; for the first time, if you wanted to be President, you had to look good on television. But in 2008, Obama built a campaign machine which centered around social media. And today, Trump's success has more to do with social media, especially Twitter, than it has to do with television.
Trump's not a fluke; he's the second Ron Paul in a row. Both these candidates did better with social media than with traditional media, but one came before a major shift in the relative importance of these two categories of media, and the other one came after it. So, while TV and print could smirk about social media in 2011, it's Trump doing the smirking today, because social media now matters more than TV and print.
Or at least, it was Trump doing the smirking a few weeks ago. His campaign's not doing as well against Clinton as it did against other Republicans. I won't go any deeper into that, because I don't want to claim to predict the future.
But if you want to understand Trump, he's a lot less mysterious if you look at him as continuining what Ron Paul began, within his party, and continuining what Obama began, in terms of campaign tactics.
(Whether he knows he's continuining either of those things is another question. I doubt Trump's ego could handle acknowledging the reality that he's picked up on the tactics a black man pioneered, and that he's only able to pick them up today because they've become a lot simpler to use, and more readily available to less educated and intelligent people like himself. Hell, even putting aside his racism, his ego's probably so fragile that he couldn't even deal with the idea that he's doing something that Ron Paul did first.)
Update: I also like this theory.