During the 2000 campaign, George W. Bush and many conservative commentators attacked Al Gore for engaging in "class warfare" after Gore promised to help the little guy and criticized Bush for favoring the rich. Four years later, the Republicans, using a page from the same playbook, attacked John Kerry and John Edwards for being populist class warriors because of their talk of Two Americas.

In this year's campaign, there's a big difference, at least so far. John Edwards, Hillary Clinton and Barack Obama have all used robustly populist language about the problems facing America's have-nots, but this year the attacks for engaging in class warfare have largely disappeared.

The reason for this may well be that the news media, political commentators and even many Republicans have come to recognize that income inequality has grown far worse and that many Americans are angry about the widening gap between those at the top and everyone else.

In recent years, the statistics regarding income disparity in America have been startling. After-tax annual income for the bottom fifth of American households inched up just 6 percent form 1979 to 2005, according to the Congressional Budget Office. During that time, income for the middle fifth of households grew by a modest 21 percent, with much of that gain caused by women in many households working more hours. Over that same period, income for the top fifth of households jumped by an impressive 80 percent, while income for the top 1 percent more than tripled, soaring by 228 percent.

The highest-earning fifth of households received 51.6 percent of the nation's after-tax income in 2005, meaning that the income of the top fifth exceeded that of the bottom four-fifths. As for the top 1 percent of households, they received more after-tax income than the bottom 40 percent, according to the Congressional Budget Office. A study that Thomas Piketty and Emmanuel Saez did based on federal tax returns found that the top 1 percent of households, averaging $1.1 million in annual income, received nearly 22 percent of all reported income in 2005, up from 9 percent in 1980. That income shift helped create the greatest level of inequality since the Roaring Twenties.

Lawrence Summers, the former Harvard president and Treasury Secretary, found that were it not for this increased inequality the bottom 80 percent of Americans would be doing considerably better. If the distribution of income today were the same as in 1979, Summers said, assuming the same level of economic growth since then, income of the bottom 80 percent of Americans would be about $670 billion more a year--or about $8,000 per family. For many households in the bottom half, this would mean a welcome 20 to 30 percent increase in income, perhaps the boost needed to avoid foreclosure.

An objective outsider who laid fresh eyes on America's economic scene, a twenty-first century Tocqueville, would probably think that the federal government would be eager to use tax policy to offset these widening disparities.But the tax cuts that President Bush and Congress enacted since 2000 have in many ways aggravated the disparities, according to statistics from the Tax Policy Center, a respected, nonpartisan research group. Those tax cuts gave $20 on average to the bottom 20 percent of American households, $744 on average to the middle fifth, and $118,477 to those with income or more than $1 million annually.

One can see the economic divide widen in another way. The average income for the top 1 percent of households was ten times that for the middle fifth in 1979. By 2005, those in the top 1 percent earned 21 times as much as those in the middle. Income for the top 1 percent of households averaged 70 times that of households in the bottom fifth, the greatest gap on record, up from 23 times as much in 1979.

At the pinnacle of the inequality pyramid are the nation's CEOs. American corporations may be tightfisted about raises for most workers, but they paid their chief executives $10.5 million on average in 2005, including salary, bonuses and stock options. That was quadruple their pay a dozen years earlier. This means the typical CEO earns 369 times as much as the average worker, up from 131 times in 1993 and 36 times in 1976.

Reducing inequality won't be easy, but according to many economists, there are numerous measures that would help, among them increasing taxes on the richest Americans, increasing the earned income tax credit, ensuring greater educational opportunities to those at the bottom, making it easier to unionize low-wage workers and doing more to preserve manufacturing industries that pay middle-class wages.

When I give speeches about my new book, The Big Squeeze, Tough Times for the American Worker, (see stevengreenhouse.com), I often ask the audience, "Was it Jesse Jackson, Ralph Nader or John Edwards who said the following?"

"The average American went exactly nowhere on the economic scale" over the past two decades. "He's been on a treadmill, while the superrich have been on a spaceship." The person who actually said that was Warren Buffett, now America's richest person.

Buffett, known as the Oracle of Omaha, had another surprising insight: "There's class warfare all right, but it's my class, the rich class, that's making war and we're winning."

What is little understood is that those who accuse others of class warfare as they seek to silence anyone who criticizes America's worsening income inequality are slyly engaging in a form of class warfare themselves--with the aim of defending the interests of those at the very top of the income pyramid.