A Just and Generous Nation has appeared just in time. Just in time for the 2016 presidential campaigns—and for the Democrats to learn a thing or two about American history.

When Sen. Bernie Sanders spoke at Georgetown University to explain what he means when he says he is a “democratic socialist” in November, he may have waited too long do so. Given Hillary Clinton’s lead in the polls, her endorsements, and the vast amount of money she has raised, it may now be all but impossible for Sanders to prevail. And yet, he must stay in the race for the nomination—not only to pull Clinton to the left, but also to continue to cultivate Americans’ progressive historical memory.

For if Americans are to confront the crises we face and redeem the nation from 40 years of class war from above—a class war that has devastated America’s industries and public infrastructures, created plutocratic inequalities of wealth and power, and empowered corporate executives and conservative politicians to lay siege to the hard-won rights of workers, women, and blacks—then we need to remember what truly has made America great, if not, dare I say it, exceptional.

It may not be true that we “have it in our power to begin the world over again” as Thomas Paine fervently told his fellow citizens-to-be in his revolutionary pamphlet Common Sense. But as the crises, struggles, and events of the 1770s, 1860s, and 1930s and 1940s—not to mention the 1960s—powerfully attest, when we have gotten it in our heads to rise up and harness the powers of democratic government to secure America’s purpose and promise, we not only have succeeded in defending the United States against powerful enemies, but also in making it both stronger and more prosperous and freer, more equal, and more democratic in the process.

Not too surprisingly, the 2016 GOP candidates have been doing everything they can to ignore or suppress the memory of that history. Ever since Ronald Reagan ran for the presidency in 1976 and, far more successfully, in 1980, Republicans have done their damnedest to not simply hijack history but also to bury it.

Evidently enamored of the Gilded Age and the prospect of returning us to it, conservatives have either repeatedly lied about the progressive and social-democratic achievements of 20th-century America or, as we have witnessed at the debates, spoken as if all of it had never happened.

Of course, prior to Bernie’s Georgetown speech recalling FDR’s New Deal initiatives and vision of an Economic Bill of Rights, LBJ’s Great Society and War on Poverty, and Martin Luther King’s commitment to democratic socialism, the Democrats had done little to historically challenge the Republicans. Yes, Hillary launched her campaign at the FDR Four Freedoms Park in New York City. And yes, Bernie cutely remarked at the Democratic debate in Des Moines, Iowa, that he is less of a socialist than was Republican President Dwight Eisenhower because he would not seek to raise taxes on the rich to the level that had prevailed during Ike’s administration in the 1950s. However, Clinton, Martin O’Malley, and Sanders have made no real effort to remind Americans of how the nation’s greatest generations and greatest leaders triumphed over the crises they confronted and, in that light, what we might endeavor to do today.

If the Democrats want to do more than win the presidency and carry out, as Bernie Sanders declares, a “political revolution,” they need to start redeeming America’s greatest generations and those who inspired and led them. They need to lay claim to our greatest radicals and to our greatest presidents. Not just FDR—but also Washington and, especially, Lincoln.

All of those forefathers came to pursue both radical-democratic action and progressive nation-building. Roosevelt himself observed in the early 1930s that it was time for the Democrats to lay claim to not just the Democratic-Republican Thomas Jefferson (whom he liberated from Southern control), but also the Republican Abraham Lincoln (whom he was convinced the GOP had abandoned long ago). And FDR definitely had in mind not just Lincoln the Emancipator, but also Lincoln the Nation Builder. In fact the 32nd president regularly quoted the 16th president to explain his own view of the role of government: “The legitimate object of government is to do for a community of people whatever they need to have done, but cannot do at all, or cannot do as well for themselves, in their separate and individual capacities.”

Long before Orwell wrote 1984, FDR knew the struggle for the present and future begins as a struggle for the past. His best Fireside Chats and speeches were essentially history lessons—lessons in which he reminded his fellow citizens of America’s purpose and promise as the great experiment in freedom, equality, and democracy and explained to them how his New Deal initiatives embodied the nation’s finest values and aspirations. Moreover, he reminded Americans that what had been achieved by earlier generations came not simply by executive action from above, but by way of struggles from the bottom up.

If the Democrats hope to counter 40 years of Reaganesque rhetoric hyping limited government, lower taxes, and corporate freedom, they ­need to emulate their too-long-neglected presidential champion, FDR. They need to study up on U.S. history and make clear to their fellow Americans how their progressive arguments and policy proposals emanate from the best of American history and politics.

With those labors in mind, I heartily recommend that Hillary, Martin, and Bernie read Holzer and Garfinkle’s new book on Lincoln and his legacy.

A Just and Generous Nation is a work of two parts. In part one, Holzer and Garfinkle portray Lincoln as a man who was convinced that America had been created for a purpose—to make real the Declaration’s proposition that “all men are created equal” and its promise of “life, liberty, and the pursuit of happiness”—and who came to recognize that it was his political task, challenge, and duty not simply to defend and secure that purpose and promise against those who would seek to deny them, but also—as the Preamble to the Constitution states—to pursue democratic initiatives to assure and advance them. They do not exactly say it, but Holzer and Garfinkle present Lincoln as a pioneering progressive and a “premature FDR liberal,” if not a proto social democrat. (I can already hear the shrieks of conservatives.)

Like most scholars, Holzer and Garfinkle—the former, a leading Lincoln biographer, the latter, an accomplished economist and businessman—rightly insist that what drove Lincoln’s commitment to sustain the Union, to fight the Civil War, the bloodiest war in American history, and, ultimately, to abolish slavery and bring an end to the “House divided,” was his deeply held belief in America’s exceptional purpose and promise.

However, Holzer and Garfinkle offer an essentially fresh take on all of that. Without at all slighting Lincoln’s determination to hold the Union together and his hatred of slavery for what it was doing to Americans both black and white, they forcefully and persuasively argue that Lincoln’s understanding of American exceptionalism—America as the “last best hope of earth”—was that the United States was founded to be a land not just of civil equality and political democracy, but also of “economic democracy.”

Their Lincoln saw America as Tocqueville saw it: as the world’s first “middle-class nation.” Gross inequalities—slavery, the grossest of them all—denied that vision. If Americans native-born and immigrant were to develop and sustain a middle-class society in which opportunities abounded, slavery needed to be contained and in time destroyed. As Holzer and Garfinkle show by way of Lincoln’s own words, Lincoln held that in contrast to the Old Regime lands of Europe and the rest of the world past and present, the United States was founded on an idea: “the idea that this country ‘proposed to give all a chance’ and allow ‘the weak to grow stronger.’” Therefore, the Union had to prevail over the Confederacy to assure the survival of America’s world-historic purpose and promise and slavery had to be destroyed to guarantee that purpose and promise for all Americans. And again, it was not just a matter of securing the nation’s promise, but also, of advancing it.

As Holzer and Garfinkle recount, from his early political days as a young Whig who believed in Henry Clay’s American System, through his trying times as the nation’s first Republican president, Lincoln saw government action not as inherently and inevitably a threat to liberty and economic opportunity (Republicans ain’t what they used to be!), but all the more as a potentially great democratic force that Americans might harness to foster economic growth and development, create opportunities, and empower working Americans to make something of themselves and the nation.

Lincoln’s greatest and most radical act was to sign the Emancipation Proclamation. But even in the midst of the horrors of war, he and the congressional Republicans applied the powers of democratic government to nation building. Most notably, in 1862 he signed into law both the Homestead Act, affording low-priced 160-acre tracts of Western lands to settlers, and the Morrill Act, aka the Land Grant Act, which granted public lands to states to set up public colleges. And no less historically important, he chartered the first transcontinental railroad and signed a bill that set the precedent for the later creation of the U.S. National Park system.

Isn’t all of this what Lincoln himself was saying at Gettysburg in November 1863? As Holzer and Garfinkle put it: When Lincoln spoke of a “new birth of freedom” he was referring not just to abolishing slavery, but also to that of enhancing democratic government and the chances that Americans could continue to pursue the making of a middle-class society. “Government of the people [and] by the people” had to become, as well, government “for the people.”

In the second part of their book Holzer and Garfinkle examine Lincoln’s legacy, the figures and forces that turned their backs on it, and those who sought to redeem and advance it. They take us through the Republican-dominated but anti-Lincolnian Gilded Age; the Progressive Era of Theodore Roosevelt and Woodrow Wilson; the New Deal and Second World War years of FDR and his re-articulation of Lincoln’s words and vision in the Four Freedoms; the postwar presidencies of Eisenhower, Kennedy, and Johnson, and the making of LBJ’s Lincoln-like Great Society initiatives; the Reagan Revolution and its anti-Lincolnian insistence that “government is the problem”; and through the Democratic and GOP presidencies of the past 40 years. These later chapters make their cases for FDR and against not only Ronald Reagan, but also Jimmy Carter, whose deregulation of capital and abandonment of labor paved the way for Reagan. Though I would add that Holzer and Garfinkle are much too kind to Bill Clinton, who enacted NAFTA, blundered terribly on national health care, and—bringing about the Great Recession—brought an end to FDR’s Glass-Steagall Act.

The book is flawed in other ways, as well. It presents a history from the top down. In Holzer and Garfinkle’s narrative, presidents act and we all watch and benefit or suffer the consequences. Before writing, Holzer and Garfinkle should have read the works by James Oakes, Ira Berlin, and John Nichols that reveal how Lincoln was moved to act by radicals, abolitionists, and slaves and working people themselves.

Still, if Hillary, Martin, and Bernie want to redeem American democracy and save American middle-class society from the throes of plutocracy and the evils of class war from above, they would do very well to read A Just and Generous Nation.