From part 3 of David Frum's generally excellent review of Charles Murray's Coming Apart:
Back in 1962, no individual American controlled a national television network, as Rupert Murdoch does today. (The legendary William Paley owned only about 10% of the stock of CBS.)
Back in 1962, it was considered shocking, and even frightening, for an extremely rich man like Nelson Rockefeller to use his fortune to gain political office.
Back in 1962, most political donations were kept secret. But when it came to light after Watergate that insurance magnate W. Clement Stone had donated $2 million to Richard Nixon's two presidential campaigns, Americans were scandalized. In 2004, by contrast, the John Kerry campaign and related organizations collected $75 million from only four donors.
Charles Murray deplores our present state as a betrayal of the founders' vision of the country. I am not certain of what the founders as a group would have thought about affluent people taking safaris to Africa. My guess is that Benjamin Rush would have disliked it, while Benjamin Franklin would have been untroubled—but who knows?
But here's what we do know: almost unanimously, the Americans of the 1790s agreed that vast inequality of fortunes—at least as between white men—were inimical to Republican government. Here for example is Noah Webster, writing in 1790 (I've corrected his idiosyncratic spelling):
The causes which destroyed the ancient republics were numerous; but in Rome, one principal cause was the vast inequality of fortunes.
The basis of a democratic and a republican form of government is a fundamental law favoring an equal or rather a general distribution of property. It is not necessary nor possible that every citizen should have exactly an equal portion of land and goods, but the laws of such a state should require an equal distribution of intestate estates, and bar all perpetuities.
It's worth noting that Noah Webster was a Federalist, not a radical Republican. What he wrote there would have received nods from almost every member of the founding generation, John Adams most emphatically, but also the aristocratic Thomas Jefferson. Jefferson went so far as to endorse a progressive income tax in a 1785 letter to James Madison.
(And here you thought the idea came from Karl Marx, or possibly Saul Alinsky.)
Republican government rested on a broad equality of fortunes: that was conventional wisdom in the founding generations.
Concentration of fortunes threatened republics: that was conventional wisdom too.