That’s how one reviewer describes the experience of watching Harvey Weinstein’s latest film. Only the movie in question isn’t “Erased,” Weinstein’s pulse-pounding thriller about an ex-CIA agent on the run. Nor is it “Only God Forgives,” in which Ryan Gosling finds himself caught up in a gritty underground world of Thai drug smuggling, prostitution, rape, and murder.

The movie is, in fact, a documentary, but one more disturbing than international criminal conspiracies and more devastating than any “Sharknado.” It’s about income inequality. As Clinton Labor Secretary Robert Reich intones in the film, “Of all developed nations, the United States has the most unequal distribution of income, and we’re surging towards even greater inequality.”

“Inequality for All,” directed by Jacob Kornbluth and set to be released nationwide on Sept. 27, comes at a critical moment for America. Sept. 15 marks the five-year anniversary of the collapse of Lehman Brothers — fueled by a toxic combination of deregulation, subprime lending and credit-default swaps — that precipitated the 2008 global economic crisis and laid bare the rot at the heart of our economic system. It was largely this orgy of greed that led the first Occupy Wall Street protesters to Zuccotti Park on Sept. 17, two years ago next week.

In the half-decade since Wall Street’s self-induced crash, the country has hovered between outrage (that the perpetrators walked off scot-free and bonus-laden) and apathy (that anything will ever break the iron bond between Congress and the financial industry).

Until now, hopefully. Following the diminutive Reich on his “statistics-driven and impassioned” crusade, “Inequality for All” throws into sharp relief the numbers and stories we hear. Combining footage from Reich’s electrifying Berkeley lectures with interviews, news clips and rich graphics, the film weaves a compelling narrative about how and why, since the late 1970s, income inequality has risen to crisis levels.

The facts are breathtaking. In 1978, according to Reich, a “typical male worker” made $48,302, while the typical top 1 percenter earned $393,682, more than eight times as much. In 2010, even as overall gross domestic product and productivity increased, the average male worker’s wage fell to $33,751. Meanwhile, the average top 1 percent earner was making more than $1.1 million — 32 times the average earner.

Reich cleverly illustrates how the graph of American inequality over the past century looks like a suspension bridge — peaking in the 1920s, leveling out because of strong, progressive policymaking in the 1950s and 1960s, and spiking again from the Reagan years through the present. We see the consequences in middle-class families that have fallen off that bridge and are struggling to stay afloat.

The film’s most refreshing figure may be Nick Hanauer, a millionaire pillow company CEO who made a fortune as an early investor in Amazon.com. Hanauer acknowledges that he earns 1,000 times the average American but that he will never generate a proportionate amount of economic activity — because he will never need 1,000 Audis or 1,000 pairs of jeans. As he puts it, “Even the richest people only sleep on one or two pillows.”

That’s why this mind-boggling income gap isn’t just bad for families — it’s terrible for the whole economy. Research shows that the increasing chasm between the top 1 percent and everybody else has slowed our nation’s economic growth.

Reich breaks down the passel of complex factors — from the rise of globalization to the decline of union membership, from stagnant middle-class wages to reduced tax rates for the richest, from deregulation to de-funding education, from Wall Street lobbyists to their friends on the Supreme Court — that have converged to squeeze the middle class dry. With his signature heart and humor, he breaks through the cynicism fomented by an intransigent political class, offering some measure of hope to a worn-out electorate.

Indeed, what makes “Inequality for All” unique even among social-issue documentaries is that it aims not just to educate and entertain but also to empower. Kornbluth and his team are launching a grass-roots mobilization effort, complete with a team of field organizers, to coincide with the film’s release. Labor unions, campus groups and a range of progressive organizations will host viewing parties to connect moviegoers with opportunities to fight income inequality. For example, student groups might hold watch parties and then organize participants to focus on college affordability issues, while unions might galvanize people to advocate for a higher minimum wage.

In short, this is a motion picture designed to put people in motion. From an interactive Web site to a teacher toolkit to a “Save the Middle Class National Tour” that will launch in January on the 50th anniversary of the War on Poverty, “Inequality for All” intends to engage ordinary people to advocate for pro-middle-class policies in all 50 state capitals.

Reich concludes his Berkeley course on wealth and poverty by stressing the power of his students — and all citizens — to make change. Free and fair markets don’t just happen; governments, elected by voters, set the rules by which they work. For all of Washington’s gridlock, then, it is still up to the American people to stand up and fight to make the market work better — not just for some, but for all.

Democracy is not a spectator sport, this film reminds us. And in this case, neither is movie-going.

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