As President Obama said in his inaugural address, America "cannot succeed when a shrinking few do very well and a growing many barely make it."
Not even the very wealthy can continue to succeed without a broader-based prosperity. That's because 70 percent of economic activity in America is consumer spending. When most Americans are becoming poorer, they're less able to spend. Without their spending, the economy can't get out of first gear. That's a big reason the recovery continues to be anemic.
Almost a quarter of all jobs in America now pay wages below the poverty line for a family of four. The Bureau of Labor Statistics estimates that over the next decade, seven out of 10 growth occupations will be low-wage - like serving customers at big-box retailers and fast-food chains.
At this rate, who's going to buy all the goods and services America is capable of producing? We can't return to the kind of debt-financed consumption that caused the bubble in the first place.
It's not a zero-sum game. Wealthy Americans would do better with smaller shares of a rapidly growing economy than with the large shares they now possess of an economy that's barely moving.
If they were rational, the wealthy would support public investments in education and job training, a world-class infrastructure (transportation, water and sewage, energy, Internet) and basic research - all of which would make the American workforce more productive.
If they were rational, they'd even support labor unions, which have proven the best means of giving working people a fair share of the nation's prosperity.
But labor unions are almost extinct. The decline of unions in America tracks exactly the decline in the bottom 90 percent's share of total earnings, and the shrinkage of the middle class.
In the 1950s, when the U.S. economy was growing faster than 3 percent a year, more than a third of all working Americans belonged to a union. That gave them enough bargaining clout to get wages that allowed them to buy what the economy was capable of producing.
But as of 2012, only 6.6 percent of American workers in the private sector were unionized, the lowest rate of unionization in almost a century.
What's to blame? Partly globalization and technological change. Globalization sent many formerly unionized jobs abroad. Technologies have replaced many formerly unionized workers in telecommunications (remember telephone operators?) and clerical jobs.
But other nations subject to the same forces have far higher levels of unionization than America. About 28 percent of Canada's workforce is unionized, as is more than 25 percent of Britain's and almost 20 percent of Germany's.
Unions are almost extinct in America because we've chosen to make them extinct.