In 2009, Barack Obama became President of the United States as a severe recession was throwing millions out of work, driving the unemployment rate to 10%. In 2011 protesters calling themselves Occupy Wall Street camped out in New York City’s Zuccotti Park, where volunteers served vegan fare. One survey found that a third had incomes over $100,000.

President Obama and Pope Francis — meeting at the Vatican in late March — endorse each other’s critique of excess capitalism and rising rates of inequality. (For more on the Pope see “The World’s 50 Greatest Leaders.”) But before getting carried away by the joint power behind the inequality theme, let’s put the U.S. problem in its own perspective — with some fresh research.

Look across three decades of increased global competition and human-replacing technology, and there’s no doubt that the American rich fared dramatically better than everyone else. But have middle-class incomes really stagnated? Brookings economist Gary Burtless examined new Congressional Budget Office numbers — which, unlike Census figures, don’t ignore income from tax cuts and in-kind benefits like health insurance — and found noticeable gains in living standards. True, from 1979 to 2010, the after-tax real incomes of the top 1% of Americans tripled. But middle-class households saw after-tax income gains of 40%. “What the CBO statistics do not show,” Burtless concludes, “is that middle- and low-income families have failed to share in the nation’s long-term prosperity.”

Conventional political wisdom also holds that social mobility in the U.S. dropped over that same period; in other words, it’s now harder to move ahead than it was in the golden era of the ’50s and ’60s, when incomes were far more equal. But another surprising study — this one from a team led by Harvard economist Raj Chetty — found that nothing had changed. In fact, “measures of social mobility have remained remarkably stable” since the 1950s. Of course, that’s not good news either. It means that for all the well-intended social interventions, we still have an entrenched class of poor with limited pathways forward.

Education levels fuel the income divide, with college degrees paying higher premiums than ever and high school graduates seeing their earnings fall. Likewise, technological advances are winnowing out middle-class jobs — while the big investment dollars chase tech companies with limited jobs. (A true believer of the inequality crusade might ask, Should a President block Facebook spending $19 billion on WhatsApp with a mere 53 employees?)

Income inequality is not a powerful motivator with American voters. Yes, a majority support increasing the minimum wage — which Obama says is the centerpiece of his war on inequality. Yes, people express concern about inequality and tell pollsters they want to raise taxes on the rich. But concern about inequality ranks well behind jobs, the economy, and health care on voters’ lists of concerns. People care more about their own conditions — whether they can pay the bills, whether their kids have a chance at upward mobility — than they do about how much a Greenwich hedge fund manager is making. Argentines rioting in 2001 were responding to severe economic conditions on the ground — just like more recent protesters in Brazil, Spain, and Greece. For all the real economic pain Americans have felt, especially since the Great Recession, it never reached those levels.

Politically, Obama’s focus on income inequality stirs his liberal base, gives Democrats and union leaders a pre-election talking point, and shifts the conversation away from problems plaguing Obamacare. But while this campaign gets plenty of media attention, for the average American it has the same political shelf life as, say, Occupy Wall Street.

This story is from the April 7, 2014 issue of Fortune.