This spiral is most apparent in declining tax rates on corporations and on top personal incomes (much in the form of wider tax loopholes), along with a profusion of government bailouts and subsidies (to Wall Street bankers, hedge-fund partners, oil companies, casino tycoons, and giant agribusiness owners, among others).
The vicious cycle of wealth and power is less apparent, but even more significant, in economic rules that now favor the wealthy.
Billionaires like Donald Trump can use bankruptcy to escape debts but average people can't get relief from burdensome mortgage or student debt payments.
Giant corporations can amass market power without facing antitrust lawsuits (think Internet cable companies, Monsanto, Big Pharma, consolidations of health insurers and of health care corporations, Dow and DuPont, and the growing dominance of Amazon, Apple, and Google, for example).
But average workers have lost the market power that came from joining together in unions.
It's now easier for Wall Street insiders to profit from confidential information unavailable to small investors.
It's also easier for giant firms to extend the length of patents and copyrights, thereby pushing up prices on everything from pharmaceuticals to Walt Disney merchandise.
And easier for big corporations to wrangle trade treaties that protect their foreign assets but not the jobs or incomes of American workers.
It's easier for giant military contractors to secure huge appropriations for unnecessary weapons, and to keep the war machine going.
The result of this vicious cycle is a disenfranchisement of most Americans, and a giant upward distribution of income from the middle class and poor to the wealthy and powerful.
Another consequence is growing anger and frustration felt by people who are working harder than ever but getting nowhere, accompanied by deepening cynicism about our democracy.
The way to end this vicious cycle is to reduce the huge accumulations of wealth that fuel it, and get big money out of politics.
But it's chicken-and-egg problem. How can this be accomplished when wealth and power are compounding at the top?
Only through a political movement such as America had a century ago when progressives reclaimed our economy and democracy from the robber barons of the first Gilded Age.
That was when Wisconsin's "fighting Bob" La Follette instituted the nation's first minimum wage law; presidential candidate William Jennings Bryan attacked the big railroads, giant banks, and insurance companies; and President Teddy Roosevelt busted up the giant trusts.
Bernie Sanders's presidential campaign is part of this mobilization.