In 2008, the downward-spiraling economy was a unifying issue for presidential candidates, voters, workers and corporate executives alike. There were disagreements about who was at fault, and what should be done to fix it, but those differences paled in comparison to the universal reaction to the frightening reality: the global economy was on the verge of a meltdown, and everyone, no matter their respective wealth, was going to suffer if things didn’t turn around.

Seven years later, things are indeed turning around. Unemployment, once in double digits, is now down to a bearable, almost normal, 5.5 percent, and the economy writ large (a somewhat stagnant first quarter 2015 notwithstanding) is growing steadily. New jobs are being created at a fast clip; with the exception of a disappointing April, more than 200,000 new jobs a month have come into the market for more than a year running. Now that the rubble has been cleared from the Great Recession, Americans have stopped bonding over the shared experience of the economic near-disaster and its aftermath. And people on the low- and middle segment of the income spectrum have started to demand answers to a deeper and longer-in-development problem: why are the people at the top making so much money, while others work full time and must still rely on federal assistance to buy food and afford housing?

Income inequality isn’t new, but it’s the new economic issue of the campaign season. Presidential candidates in both parties are addressing it in speeches (though with different prescriptions to narrow the wealth gap). The question has entered into legislative debates in both Congress and the states, on issues ranging from tax cuts to raising the minimum wage, imposing conditions on government assistance dollars, or giving the president fast-track authority to negotiate an international trade pact. And struggling Americans are looking at the top earners and wondering: is the American Dream dead?

A Gallup poll released this week shows that Americans are feeling increasingly in economic retreat. Barely half (51 percent) now consider themselves as being part of the middle or upper classes, compared to an average of 61 percent during 2000-08. A full 48 percent say they are now in the working or lower classes.

To a liberal audience, the culprits are the GOP congressmen and governors who refuse to fund social safety net programs, raise state and federal minimum wages, and give tax breaks to the wealthy. But a quick look at history shows that the stratification of wealth grew enormously under former President Bill Clinton. During the economic expansion of 1993-2000, real income growth among the top one percent of earners almost doubled; for the lower 99 percent on the economic totem pole, real income grew by 20 percent, according to an analysis prepared by Emmanuel Saez, an economics professor at UC Berkeley. That meant that 45 percent of the economic growth during that period was captured by the small, one-percent sliver of Americans. The reason no one seemed to notice -- or at least, care – was that virtually all economic boats were lifted by the rising tide, with average income in real terms growing by nearly a third for the population as a whole. During the 2002-07 economic expansion during the George W. Bush years, the super-wealthy did even better, percentage-wise, capturing 65 percent of the income growth.

Fast forward to the Great Recession (defined as 2007-09, although most Americans were not feeling in “recovery” in 2010), and the highest earners indeed took a tougher hit, seeing real incomes drop 36 percent, compared to about 12 percent for the lower 99 percent. But again, the uber-rich made up for it in the recovery, capturing an astonishing 91 percent of the real income expansion, according to Saez.

Those trends make Americans and politicians worry about economic mobility and the future of the middle class. Not only are middle-class Americans a key part of the electorate, but they also play a big role in the economy as a whole. Some 70 percent of the U.S. economy is consumer-driven, and it’s the middle class that tends to buy things like appliances and cars that keep the system humming (investments by the wealthy also create jobs, conservatives note, by establishing new businesses and expanding existing ones).

Some of it, says Salim Furth, an economist with the conservative-leaning Heritage Foundation, is unavoidable in a global, higher-tech economy – and it may not be such a bad thing. When people talk about “income inequality,” he says, they’re really talking about poverty, which is and always has been a problem. Poor people have lower health outcomes and other issues, Furth notes, whereas there’s not much difference once you consider families making more than about $50,000 a year. What appears to be a widening of the wealth gap is “the people who were super-wealthy have been superseded by people who are even super-wealthier,” he says. Years ago, someone might have become a millionaire by selling a lot of refrigerators in the U.S. Now, he notes, someone can become a billionaire by developing a new smartphone.

And while some things are increasingly expensive – such as houses – other items developed by the technology sector are cheap and getting cheaper, he says, noting that it would have seemed unthinkable decades ago that a low-income person would carry a cell phone.

Demographics also affect the dispensation of wealth, adds Mark Frank, economics professor at Sam Houston State University. During the latter part of the 20 th century, he says, women and ethnic minorities fought discrimination, and their salaries were increased (though not to the average level of white men). There’s also the theory of “assortive mating,” he says, with female earners marrying men with similar wealth potential.

DATE MINE: Wealth Inequality Has Widened Along Racial Lines ]

And changes in the national and world economy – deindustrialization, globalization and the decline of labor unions – have also affected the equation. During the height of the modern industrial era, someone without a college degree could get a secure, well-paying job at an automobile factory. Now, many of those jobs have moved overseas, where labor is cheaper, and the higher-tech jobs here require education not all American workers have.

“The root cause from our perspective is reduced bargaining power,” says Josh Bivens, research and policy director at the liberal-leaning Economic Policy Institute. Labor union membership has shrunk, and governors across the nation have been successful in weakening the bargaining power of public sector unions, he notes. That, he said, is a major reason the minimum wage, in real terms, is lower than it was in 1968, while productivity has increased 80 percent since then.

Democrats have been heralding a minimum wage increase to help low-income workers. Investments in infrastructure have also been touted as a way to create middle-class jobs. Republicans are sensitive to the issue (it’s unlikely we’ll hear a 2016 candidate repeat Mitt Romney’s lament about the “47 percent” who live off the government’s largesse), but the answers are dramatically different. “The best way to drive up wages is to expand opportunity,” says Sen. Lindsey Graham, a South Carolina Republican mulling a presidential run.

And even Democrats are changing the playbook from the days of knee-jerk protectionism, and are considering international trade agreements which once would have been seen as automatically damaging to U.S. workers. Virginia, for example, used to have an insular economy, but now – with its port and international airport – relies on global trade for growth, notes Sen. Tim Kaine, a Virginia Democrat. Globalization is happening, Kaine says, and “we are either going to be the leaders, like we have been since World War II, or we’re going to step back and let others do it.”