It's not just the wealthiest one per cent.
Fully 20 per cent of US adults become rich for parts of their lives, wielding outsize influence on America's economy and politics. This little-known group may pose the biggest barrier to reducing the nation's income inequality.
The growing numbers of the US poor have been well documented, but survey data provided to The Associated Press detail the flip side of the record income gap - the rise of the "new rich".
Made up largely of older professionals, working married couples and more educated singles, the new rich are those with household income of $US250,000 ($A275,983) or more at some point during their working lives. That puts them, if sometimes temporarily, in the top two per cent of earners.
Even outside periods of unusual wealth, members of this group generally hover in the $US100,000-plus income range, keeping them in the top 20 per cent of earners.
Companies increasingly are marketing to this rising demographic, fuelling a surge of "mass luxury" products and services from premium Starbucks coffee and organic groceries to concierge medicine and VIP lanes at airports.
They're not the traditional rich.
In a country where poverty is at a record high, today's new rich are notable for their sense of economic fragility. They're reached the top two per cent, only to fall below it, in many cases. That makes them much more fiscally conservative than other Americans, polling suggests, and less likely to support public programs, such as food stamps or early public education, to help the disadvantaged.
New research suggests that affluent Americans are more numerous than government data depict, encompassing 21 per cent of working-age adults for at least a year by the time they turn 60. That proportion has more than doubled since 1979.
At the same time, an increasing polarisation of low-wage work and high-skill jobs has left middle-income careers depleted.
As the fastest-growing group based on take-home pay, their success has implications for politics and policy.
The group is more liberal than lower-income groups on issues such as abortion and gay marriage, according to an analysis of General Social Survey data by the AP-NORC Center for Public Affairs Research. But when it comes to money, their views aren't so open. They're wary of any government role in closing the income gap.
In Gallup polling in October, 60 per cent of people making $US90,000 or more said average Americans already had "plenty of opportunity" to get ahead. Among those making less than $US48,000, the share was 48 per cent.
Sometimes referred to by marketers as the "mass affluent," the new rich make up roughly 25 million US households and account for nearly 40 per cent of total US consumer spending.
While pay shrank for most Americans after the 2007-2009 recession, theirs held steady or edged higher. In 2012, the top 20 per cent of US households took home a record 51 per cent of the nation's income. The median income of this group is more than $US150,000.
Paul F Nunes, managing director at Accenture's Institute for High Performance and Research, calls this group "the new power brokers of consumption". Because they spend just 60 per cent of their before-tax income, often setting the rest aside for retirement or investing, he says their capacity to spend more will be important to a US economic recovery.
Economists say the group's influence will only grow as middle-class families below them struggle. Corporate profits and the stock market are hitting records while the median household income of $US51,000 is at its lowest since 1995. That's a boon for upper-income people who are more likely to invest in stocks.
At the same time, some 54 per cent of working-age Americans will experience near-poverty for portions of their lives, hurt by globalisation and the loss of good-paying manufacturing jobs.
Both Democrats and Republicans are awakening to the political realities presented by this new demographic bubble.
Traditionally Republican, the group makes up more than one in four voters and is now more politically divided, better educated and less white and male than in the past, according to Election Day exit polls dating to the 1970s.
Sixty-nine per cent of upper-income voters backed Republican Ronald Reagan and his supply-side economics of tax cuts in 1984. By 2008, Democrat Barack Obama had split their vote evenly, 49-49.
In 2012, Obama lost the group, with 54 per cent backing Republican Mitt Romney. Still, Obama's performance among higher-income voters exceeded nearly every Democrat before him.