There are far more ordinary wage-earning people than wealthy investors and corporate moguls, but the political right has done far better at using class solidarity to its advantage than the liberal left. Americans like to view their country as a wide-open land of opportunity. Most consider themselves middle class, and most are uneasy thinking in terms of class at all. It's the rich who understand and act on class interests.

The Bush presidency has intensified a trend that began under Ronald Reagan -- widening inequality that benefited those at the very top. This shift has been carried out not just through tax policy but through cuts in social outlays and changes in regulations that made it easier for chief executives and other financial insiders to enrich themselves at the expense of ordinary workers and small investors and harder for ordinary people to afford decent schools, houses, and health care. This is surely class warfare, but it is one-way.

Under Bush, the pay of ordinary workers has lagged behind inflation. About 77 percent of all the dollars in tax cuts went to the richest 20 percent of households. More workers have lost health insurance and pension coverage. These policy changes did not just happen; they were worked out in concert with organized business.

You would think, therefore, that the Democrats would make Republican responsibility for these skewed benefits and costs the centerpiece of the 2004 campaign. But that enterprise is trickier than it might seem. Since all but the most destitute of voters consider themselves middle class, a politics that talks about haves and have-nots starts sounding like a politics of handouts.

While John Edwards bravely speaks of two Americas, John Kerry constantly invokes "the middle class." It's not that Kerry opposes programs that benefit the poor; it's that polls consistently show that if you emphasize the poor you run smack into the fact that most Americans consider themselves middle class.

Even though individual voters may resent the fact that jobs are moving to India or that schools are lacking necessary funds or that health care benefits are evaporating, this is not a country where most voters resent the rich as a class. It's a land where nearly everyone would like to be rich.

Paradoxically, Republicans bump up against this reality when they try to damn John Edwards as a rich trial lawyer. In fact, Edwards was a poor boy who made good and then used his legal skills to help a lot of ordinary plaintiffs collect their due. Were he a corporate attorney rather than a personal injury lawyer, he'd be a Republican rags-to-riches poster boy.

But because nearly everyone identifies upward, you don't gain traction in American progressive politics by baiting the rich. In a now-famous piece of research titled "Homer Gets a Tax Cut," the Princeton political scientist Richard Bartels demonstrated that even the poor supported tax cuts for the rich because they hoped that they might possibly benefit.

The politics of class in America is further complicated by social issues. If Kerry's pocketbook program had a clean debate with Bush's, Kerry would win hands down. But a lot of working-class voters are socially conservative, and Bush's conservatism on issues of faith, family values, and flag tends to fuzz up the fact that his program doesn't serve their pocketbook interests. Bush and Kerry, of course, are both from the economic elite. But Bush, despite his upper-class program, masquerades as just plain folks.

Of recent Democratic presidents, Bill Clinton understood these dynamics best. He could articulate a politics of "putting people first" that united the pocketbook interests of middle-class voters and poor ones. When he said that people who worked hard and played by the rules shouldn't be poor, he made economic populism sound socially traditionalist and safely middle class.

No modern president should be more vulnerable than George Bush on the issue of having failed to stick up for the economic interests of ordinary Americans. But so far the Democrats have been more mindful of the volatility of the class issue than its political potential.

The fact that Kerry, at this point in the campaign, is only fighting Bush to a draw suggests that Democrats still have a lot of work to do to smoke out the almost un-American issue of class. If they do, Kerry will win going away.

Robert Kuttner is co-editor of The American Prospect. This column originally appeared in The Boston Globe.