Four years ago, in the first draft of my book “A Capitalism for the People,” I had a section dedicated to how worrisome a Donald J. Trump presidential bid would be for America. I was not prescient. It’s just that having grown up in Italy, I knew how a real estate tycoon — in this case, Silvio Berlusconi — whose career exemplified crony capitalism could become the leader of supposed pro-market forces, and I knew what it meant for the country.

I cut this section after being told that my point was irrelevant: In America, there was no chance that a character like Mr. Trump would ever be seriously considered as a candidate.

Then 2016 happened: After sweeping wins in New Hampshire and South Carolina, Mr. Trump has shattered that notion. The Trump phenomenon caught everybody by surprise. Yet it is a manifestation of a fundamental contradiction long present in the Republican Party: Despite fierce anti-big-business sentiment among many Republican voters, no Republican candidate has emerged to champion them.

This contradiction created the space for Mr. Trump. In spite of being every bit a part of that pro-business establishment, Mr. Trump can pretend to be anti-establishment by sometimes reviling big business, because he doesn’t need its funding for his campaign.