By Bob Herbert – New York Times.

The clearest explanation yet of the forces that converged over the past three decades or so to undermine the economic well-being of ordinary Americans is contained in the new book, “Winner-Take-All Politics: How Washington Made the Rich Richer — and Turned Its Back on the Middle Class.”

The authors, political scientists Jacob Hacker of Yale and Paul Pierson of the University of California, Berkeley, argue persuasively that the economic struggles of the middle and working classes in the U.S. since the late-1970s were not primarily the result of globalization and technological changes but rather a long series of policy changes in government that overwhelmingly favored the very rich.

Those changes were the result of increasingly sophisticated, well-financed and well-organized efforts by the corporate and financial sectors to tilt government policies in their favor, and thus in favor of the very wealthy. From tax laws to deregulation to corporate governance to safety net issues, government action was deliberately shaped to allow those who were already very wealthy to amass an ever increasing share of the nation’s economic benefits.

“Over the last generation,” the authors write, “more and more of the rewards of growth have gone to the rich and superrich. The rest of America, from the poor through the upper middle class, has fallen further and further behind.”

As if to underscore this theme, it was revealed last week (by David Cay Johnston, a Pulitzer Prize-winning former reporter for The New York Times), that the incomes of the very highest earners in the United States, a small group of individuals hauling in more than $50 million annually (sometimes much more), increased fivefold from 2008 to 2009, even as the nation was being rocked by the worst economic downturn since the Great Depression.

Last year was a terrific year for those at the very top. Professors Hacker and Pierson note in their book that investors and executives at the nation’s 38 largest companies earned a stunning total of $140 billion — a record. The investment firm Goldman Sachs paid bonuses to its employees that averaged nearly $600,000 per person, its best year since it was founded in 1869.

Something has gone seriously haywire in the distribution of the fruits of the American economy.

This unfortunate shift away from a long period of more widely shared prosperity unfolded steadily, year after year since the late-’70s, whether Democrats or Republicans controlled the levers of power in Washington. “Winner-Take-All Politics” explores the vexing question of how this could have happened in a democracy in which — in theory, at least — the enormous number of voters who are not rich would serve as a check on policies that curtailed their own economic opportunities while at the same time supercharging the benefits of the runaway rich.

The answer becomes clearer when one recognizes, as the book stresses, that politics is largely about organized combat. It’s a form of warfare. “It’s a contest,” said Professor Pierson, “between those who are organized, who can really monitor what government is doing in a very complicated world and bring pressure effectively to bear on politicians. Voters in that kind of system are at a disadvantage when there aren’t reliable, organized groups representing them that have clout and can effectively communicate to them what is going on.”

The book describes an “organizational revolution” that took place over the past three decades in which big business mobilized on an enormous scale to become much more active in Washington, cultivating politicians in both parties and fighting fiercely to achieve shared political goals. This occurred at the same time that organized labor, the most effective force fighting on behalf of the middle class and other working Americans, was caught in a devastating spiral of decline.

Thus, the counterweight of labor to the ever-increasing political clout of big business was effectively lost.

“We’re not arguing that globalization and technological change don’t matter,” said Professor Hacker. “But they aren’t by any means a sufficient explanation for this massive change in the distribution of wealth and income in the U.S. Much more important are the ways in which government has shaped the economy over this period through deregulation, through changes in industrial relations policies affecting labor unions, through corporate governance policies that have allowed C.E.O.’s to basically set their own pay, and so on.”

This hyperconcentration of wealth and income, and the overwhelming political clout it has put into the hands of the monied interests, has drastically eroded the capacity of government to respond to the needs of the middle class and others of modest income.

Nothing better illustrates the enormous power that has accrued to this tiny sliver of the population than its continued ability to thrive and prosper despite the Great Recession that was largely the result of their winner-take-all policies, and that has had such a disastrous effect on so many other Americans.