In an article published just this week by Bloomberg, Cass Sunstein argues that the campaigns of both Hillary Clinton and Bernie Sanders have been focused on the wealth of the “top one percent” rather than on the betterment of the “bottom ten percent” and that this is wrong because such a focus is long on “outrage” but short on “solutions” and because this focus is at odds with the core message of the New Deal as explained in President Franklin Delano Roosevelt’s famous “Four Freedoms” speech. But it is Sunstein who is wrong. Let me count the ways.

First, he is wrong to lump Clinton and Sanders together as “operating within the terms set by top 1 percent Progressivism.” Only Sanders has been consistently operating within the terms of this discourse. Clinton is in fact clearly a partisan of Sunstein’s more meliorist and centrist approach. If she is now talking about the one per cent, it is only because the success of Sanders’ insurgent campaign has forced her to the left. Would that Sanders be who represents the current “progressive” consensus. He does not. But his success is forcing “progressives” of all stripes to take seriously his populist and social democratic message.

Second, Sunstein is wrong to locate the language of the one per cent in either of the two Democratic campaigns; this language was thrust to the center of public discourse, at least since 2012, by the Occupy movement in this country and beyond — for Occupy was a global phenomenon. This language is simplistic, as all political slogans and chants are simplistic, from “Springtime in America” to “Change We Can Believe In.” But behind the slogan is a very serious critique of long-term secular trends that have led to an enormous concentration of income and wealth among the top one percent and growing precarity below. This critique resonates widely (for one example of research that supports this claim, see “The Insecure American: Economic Experiences, Financial Worries, and Policy Attitudes”). To draw energy from this critique is not a category mistake or a foolish strategic choice. It is an acknowledgment of fundamental features of the current political economy that have been identified by many prominent political economists.

Third, Sunstein is wrong because he fails to see that “outrage” is a very productive political force, which can be mobilized for good or ill. Most of the current Republican candidates are mobilizing outrage in the name of xenophobia and fear. But the discourse of the one per cent that has been catapulted to the forefront by Sanders and is now somewhat adopted by Clinton mobilizes outrage in the name of civic equality. Is that really a bad thing? This outrage is better described as indignation at the many injustices characteristic of our current system. And indignation at its best is informed by a profound sense of dignity that is the polar opposition of resentment.

This leads to the fourth reason why Sunstein is wrong: because his article simply fails to recognize that indignation, and popular mobilization against injustice, has been the single most important source of progressive change and the expansion of civic and material equality in the history of the United States. It was precisely such indignation and such mobilization that energized the New Deal and that led FDR to denounce “economic royalists” and to pursue a broad and deep program of institutional reform. New Deal liberalism was not a form of “seriousness” belied by popular mobilization. It was a kind of “political revolution” (historian Carl Degler called it “the third American revolution”) fueled by the seriousness of popular mobilization. It was not “nudging,” but the insistent demands of popular movements and organized groups that empowered FDR to do what he did.

Sunstein is correct that slogans about “one percent” are not sufficient to mobilize a substantial movement for progressive reform, much less to generate political victories for such reform. Does the Sanders campaign have what it takes to accomplish this? I am doubtful. But this has more to do with the profound obstacles confronting economic reform than it does with the weaknesses of the campaign or its vision. Clear, however, is the understanding that it is a very good thing that a language of economic justice resonates today and that the Sanders campaign is mobilizing this energy in a productive way. Sunstein does this campaign and its activists and supporters an injustice when he implies that it is powered by naive moralizing. The moralizing is not so naive. More important, behind it is a serious strategic idea — the idea that egalitarian political-economic reforms require mass mobilization and that such mobilization involves not only primaries and elections, but also coalitions with labor unions, poor people’s movements, and civil rights organizations as well as support for the kinds of laws and policies that will allow these organizations to grow. Sanders does not simply orate about inequality. He also has sponsored a major reform of US labor law, the Workplace Democracy Act, and has spent a lifetime working to strengthen unions in the United States.

Sunstein is wrong to suggest that the left turn in the current primary debate represents mere sloganeering about “the wealthy.” To the contrary, it may represent the first possibility in decades for a serious debate about what is needed “to provide help and opportunity for the many millions of Americans who urgently need it.”