First came Occupy Wall Street, and its pitch-perfect slogan on inequality: “We are the 99 percent.” After that movement fizzled, Thomas Piketty, the handsomely ruffled French professor, released a 685-page book explaining that we really were living in a new Gilded Age in which the wealth gap was as wide as it had ever been. Finally, in June, one of the plutocrats sitting atop the piles of money he made in the digital revolution, Nick Hanauer, wrote an article in Politico magazine—it’s the most-shared story ever on Politico’s Facebook page—warning that the pitchforks were coming, and rich people like him should advocate for a healthier middle class and a higher minimum wage.

The debate over inequality is now raging, and most Americans are unhappy about the widening divide between the haves and have-nots. Hanauer has been making the same case for years, drawing heaps of both praise and scorn. Forbes magazine has alternately called Hanauer insane and ignorant. His TED University presentation calling for a $15-minimum wage was left off the organization’s website because it was deemed too “political.” That’s nothing next to Piketty’s detractors, who at their most extreme accused him of twisting his data.

Hanauer and Piketty inspire these broadsides because they are challenging, in a far more aggressive way than plutocrats and economists usually do, the conservative economic orthodoxy that has reigned since at least the 1980s. Under Ronald Reagan, we called it trickle-down economics, the idea that the men who can afford their own private jets—they’re usually men—deserve gobs of money because they provide some special entrepreneurial or innovative talent that drives the American economy.

That’s well known. Far less often discussed is the flipside of this belief: that helping the less well off will dampen the American money-generating engine—that it will hurt growth, because the only thing that inspires the “job creators” to work so hard is the promise of insanely vast financial rewards. Poverty is a necessary evil in this worldview, and helping the less well off creates a “culture of dependency,” which discourages work. “The United States thrives because of a culture of opportunity that encourages work and disdains relying on handouts,” Matthew Spalding of The Heritage Foundation wrote in 2012, neatly summing up the conservative ethos.

Conservatives have dominated discussions of poverty for a generation with arguments like this one. It’s completely wrong. It’s more than that—it’s just a lie, concocted as cover for policies that overwhelmingly favored the rich. But it took the worst economic crisis since the Great Depression for many economists, liberal or not, to finally say publicly what many had long argued: Inequality is bad for the economy.

The latest to say so is the rating agency Standard and Poor’s, not exactly a bastion of lefty propaganda. An S&P report released August 5 says that rising inequality—gaps in both income and wealth—between the very rich and the rest of us is hurting economic growth. The agency downgraded its forecast for the economy in the coming years because of the record level of inequality and the lack of policy changes to correct for it. The report’s authors argue against the notion that caring about equality necessarily involves a trade-off with “efficiency”—that is, a well-functioning economy.

To be sure, they’re not making a case for a massive government intervention to help low-income Americans. They discuss the benefits of current policy proposals—like raising the federal minimum wage to $10.10 per hour—with the caveats that such changes could have potential negative consequences—like dampening job growth. (Most economists agree that such a small hike wouldn’t have that impact.)

At its core, though, the S&P report does argue that pulling people out of poverty and closing the gap between the 1 percent and the 99 percent will increase economic growth. The authors argue for some redistributive policies, like increased financial aid for post-secondary education. “The challenge now is to find a path toward more sustainable growth, an essential part of which, in our view, is pulling more Americans out of poverty and bolstering the purchasing power of the middle class,” the authors write. “A rising tide lifts all boats…but a lifeboat carrying a few, surrounded by many treading water, risks capsizing.”

It’s an important moment for such a debate. The Great Recession was a great equalizer, a crisis in which many in the middle class, and even upper-middle class, fell all the way to the bottom and relied on the government safety net. They learned what anyone who cared to look at the data already knew: The vast majority of people relying on government benefits are suffering a temporary setback that they will recover from, as long as they have a helping hand. The holes in the safety net also became more apparent. Even Paul Ryan, the Republican congressman from Wisconsin who has set his blue eyes on higher office, adequately diagnosed many of the problems with anti-poverty programs when he introduced a new plan last month. (Whether he would actually want to pay for the changes he calls for is debatable.)

Closing the gap by lifting low-income families out of poverty could do more to help the economy than any number of tax credits for “job creators” might, which is what Hanauer argued in Politico. And the S&P report puts more support in his corner.

On the question of what to do, there is widespread agreement on boosting educational attainment and increasing salaries at the bottom end. Policymakers have had a lot of time to think about how to help the middle class, since real wages began declining in the mid-1970s. Many of the problems of inequality have policy solutions ready to go, spelled out in a white paper stuffed in someone’s desk drawer. Why has it taken so long to think about addressing it? Was the political might of the right so overwhelming that they couldn’t speak up until people like Hanauer saw, as he warned in his essay, that the pitchforks would be coming for them?