“What we now call the Reagan Revolution was a turning point in the American economy,” said Jacob S. Hacker, a political science professor at Yale University in Connecticut and author, with Paul Pierson, of “Winner-Take-All Politics.” “These patterns of rising inequality were established then.”

Economists, most notably Thomas Piketty and Emmanuel Saez, the data jocks who are the gurus of income inequality studies, have been pointing out the growing gap for a decade. But, particularly in the United States, which still determines the ideological weather for the rest of the world, that increasingly skewed distribution failed to catch fire as a political issue.

“Among elite opinion, this wasn’t talked about,” Jeffrey D. Sachs, director of the Earth Institute at Columbia University in New York and author of “The Price of Civilization,” published this month, told me. “It was viewed as impolite, it was viewed as class warfare.”

One reason the rest of society went along with that reticence is suggested by University of Chicago economist Raghuram Rajan, in his 2010 book “Fault Lines” — that the credit bubble of the 1990s and 2000s masked the stagnating wages of the U.S. middle class.

The financial crisis of 2008 brought that self-deception to an abrupt halt. And while the middle class is still in the doldrums, the top 1 percent has largely recovered, thanks in part to muscular intervention by the state. That one-two punch is why the old American taboo on talking about income distribution is lifting, particularly in Zuccotti Park.

“‘Class warfare’ has seldom had much traction in American politics because Americans tend to idealize the ‘free market’ as a separate sphere of life, with its own (rough) justice,” Larry M. Bartels, a political science professor at Vanderbilt University in Tennessee and author of “Unequal Democracy,” wrote in an e-mail reply to my questions.

“Escalating inequality and the wreckage of the Great Recession may now be focusing increasing anger on that top sliver — especially bankers, who are, conveniently, prominently implicated in the malfeasance that led to the financial meltdown of 2008 and (still) immensely rich.”