Still, the fact that Trump has come so far does not speak well of the average American voter or for democracy. For all that folks, including commentators, are critical these days of the Republican establishment, I think on balance this shows that a sense of civic responsibility in the establishment generally has been all that has been keeping the US from disaster. Otherwise, why have we not seen campaigns like Trump's before? Even previous populists—William Jennings Bryan, for example—had a strong core of principle that they would not violate. This may have been the difference between the US and, say, the Weimar Republic.
In another sense, though, we are indeed seeing the failure of the ruling classes. In part, they have grown much less principled since the Sixties or so, and so they have lost their moral authority. As happened in the Weimar Republic, where the elite became sexually libertine, and were in any case blamed for the German failure of the First World War and the postwar economic chaos. In part, I suspect, the vastly improved communication technology over the past few years—internet, social media, smart phones—has exposed their flaws to the rest of us and rendered their leadership less necessary. A Trump and his followers can now organize without them.
Apparently, there is a case to be made for elites.