The two men could hardly have been more different. One the fatherless son of a single mother, the other a scion of the most important American political family since the Adamses; one a cool, intellectual analyst, the other an instinctive gut player who never looked back once a decision was made. Yet there they were, together in the East Room of the White House on a June day in 2012, inexorably linked by history: Barack Hussein Obama and George Walker Bush.

The occasion was the unveiling of George and Laura Bush’s White House portraits. “It’s been said,” Obama told the audience, “that no one can ever truly understand what it’s like being President until they sit behind that desk and feel the weight and responsibility for the first time. And that is true. After three and a half years in office—and much more gray hair—I have a deeper understanding of the challenges faced by the Presidents who came before me, including my immediate predecessor, President Bush. In this job, no decision that reaches your desk is easy. No choice you make is without costs. No matter how hard you try, you’re not going to make everybody happy. I think that’s something President Bush and I both learned pretty quickly.”

With an ironic twinkle, Bush marked the moment with a bit of self-deprecation, or at least self-awareness: “I am … pleased, Mr. President,” Bush said to Obama, “that when you are wandering these halls as you wrestle with tough decisions, you will now be able to gaze at this portrait and ask, ‘What would George do?’”

History is full of examples of presidents thinking and talking about their predecessors, seeking inspiration or warning from the successes and the failures of those who came before. All presidents are all members of what the historians and TIME editors Nancy Gibbs and Michael Duffy have called “The Presidents Club.” The enormity of that shared experience—of the feeling of holding ultimate power, and ultimate responsibility—can create strange connections and alliances once the heat of battle has faded.

A look back suggests that the presidents appreciate what voters appreciate: leaders who at once think big and act smartly, worrying more about the service of ends than the specifics of means. For the presidents, history is always provisional, always conditional, and the greatest of leaders are the ones who—like Jefferson, Jackson, Lincoln, FDR, JFK, and Reagan—are willing to depart from dogma to make the country stronger and more secure.

So how do presidents judge other presidents? Two themes emerge. First, they often evoke their predecessors in search of sanction for present policies: they enlist—or rather conscript—the long-dead in the political wars of the moment. The second common theme, I think, is that presidents tend to see as they would be seen, and one clue to understanding how presidents think of themselves is to note how they think of their predecessors.

Two Founders

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Thomas Jefferson and George Washington were tall, rich, revolutionary Virginians—and there the similarities began to fade as the years of the early republic went on. As the first president of the infant nation, Washington asked Jefferson, then the American minister to France, to serve as secretary of state.

Arriving in New York, then the national capital, in 1790, Jefferson found himself in a city and a political culture that struck him as overly sympathetic to British and too prone to monarchial forms and habits of mind. Fresh from the intoxicating atmosphere of the early revolutionary days in France—the Terror was still in the future—Jefferson was out of phase with the prevailing ethos in the Washington administration, an ethos created and sustained in large measure by Treasury Secretary Alexander Hamilton.

As Hamilton’s adversary in the Cabinet, Jefferson became the voice—not the only one, but the central one at the highest levels—that competed most ferociously for Washington’s ear. As Jefferson said, he and Hamilton were pitted against one another daily, “like two cocks in the pit.” Washington asked them to end the “internal dissensions that are harrowing and tearing our vitals.”

Jefferson and Washington fell out and it was only years later, in 1814, that Jefferson offered a correspondent this reading of Washington: “Perhaps the strongest feature in [Washington’s] character was prudence, never acting until every circumstance, every consideration, was maturely weighed; refraining if he saw a doubt, but, when once decided, going through with his purpose, whatever obstacles opposed. His integrity was most pure, his justice the most inflexible I have ever known. … He was, indeed, in every sense of the words, a wise, a good, and a great man. His temper was naturally high toned; but reflection and resolution had obtained a firm and habitual ascendancy over it. If ever, however, it broke its bonds, he was most tremendous in his wrath….” There is much here, and perhaps the most revealing insight was about Washington’s temperament. Long celebrated for his capacity to project calm at even the most desperate of hours, Washington was, according to Jefferson’s close observation, also a man who could lose his composure, if only in private, thus showing Washington to be a very human hero.

Jefferson’s Washington is a real man who accomplished real things. More interesting than a figure of myth and legend, for figures of myth and legend are unapproachable, Jefferson’s Washington is a human being who overcame his own flaws to do great things. Which is how Jefferson himself wished to be seen.

Abe and Andy

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Several decades later, Abraham Lincoln—not even a Jeffersonian Republican, but first a Whig and then the candidate of a new and different Republican Party—turned to Jefferson as an unlikely ally.

In April 1859, from Springfield, Ill., Lincoln wrote to a group in Boston declining its invitation to speak to a Jefferson birthday celebration. The moment gave Lincoln the chance to link Jefferson to the cause of freedom in an hour of danger for the Union.

“All honor to Jefferson,” said Lincoln, “to the man who, in the concrete pressure of a struggle for national independence by a single people, had the coolness, forecast, and capacity to introduce into a merely revolutionary document, an abstract truth, and so to embalm it there, that today, and in all coming days, it shall be a rebuke and a stumbling block to the very harbingers of reappearing tyranny and oppression.” In judging Jefferson in this light, Lincoln was using a predecessor was his own political purposes, conscripting a dead slave-owner in the cause of the union.

And Lincoln, master politician that he was, also enlisted Andrew Jackson, another dead slave-owner. In an upper room over his brother-in-law’s store near the corner of Sixth and Adams in Springfield—it was called Yates and Smith—Lincoln was at work on his First Inaugural address in early 1861. The only documents Lincoln requested to have at hand as he wrote were the Constitution, Daniel Webster’s second reply to William Hayne (on the importance of union), Henry Clay’s speech on the Compromise of 1850—and Andrew Jackson’s 1832 Proclamation to the People of South Carolina attacking nullification and secession.

In a way, then, Lincoln sent for Andrew Jackson. Jackson—states’-rights man, slaveowner, scourge of the Second Bank of the United States—believed in the Union more than anything else. Part of the reason was personal: he had lost his mother and brothers in the Revolution (his father had died before he was born), had himself been a teenaged prisoner of war in the hands of the British, and he saw America, as he put it, as “one great family.” His own family’s blood had consecrated the Union, and he would not allow anything or anyone—he thought in just these apocalyptic terms—to threaten the thing he held dearest.

The example Jackson left to posterity—and now Lincoln was that posterity—was one of effective leadership in a sensitive moment in which the overall goal was achieved sometimes slowly and indirectly, but was nonetheless achieved. “The right of a state to secede is not an open or debatable question,” Lincoln had said at the end of 1860. “It was fully discussed in Jackson’s time, and denied … by him … It is the duty of a President to execute the laws and maintain the existing government. He cannot entertain any proposition for dissolution or dismemberment.”

Jackson had taken extraordinary steps in his public career to ensure the ultimate success of the American experiment, imposing martial law on New Orleans a general during the War of 1812—an example, along with the love of union, on which Lincoln drew as the 16th president struggled to lead amid the Civil War. Franklin Roosevelt later remarked that Lincoln “was a sad man because he couldn’t get it all at once. And nobody can.” FDR was largely right, but Lincoln understood the tragedy and reality of history. He knew he and his nation lived in twilight, and that nothing was perfect nor perfectible.

Two Democrats

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When FDR was a small child, he was taken to the White House by his father, James Roosevelt, who was a Grover Cleveland Democrat. President Cleveland had had a long day, and at one point put his hand on young Franklin’s head and said he had a prayer for the boy—that he might never be fated to become president of the United States.

As far as we know, few presidential prayers have ever gone as unanswered as that casual one. Franklin Roosevelt was also a great student of history. He loved the idea of himself as a player in the drama of his times (“That was the Garbo in me,” he once joked after watching himself in a newsreel), and in many ways he thought of the White House as a family property not unlike Hyde Park. It was natural, then, for him to think much about those who had come before.

Like other presidents, Roosevelt liked in others what he hoped the world would see in him. Roosevelt believed his own struggles through the Depression and later World War II were of a piece with the struggles of Jefferson and Jackson for liberty abroad and equality at home. The interest in Jackson was most evident in the 1930s; that in Jefferson most evident in the early 1940s.

In 1934 Roosevelt traveled to the Hermitage, and he insisted on walking—or “stumping,” as he put it in private, darker moments—through a tour of the house. In March 1937, he had the inaugural stand in Washington designed to as a replica of the Hermitage, a tangible sign that he believed his fights were Jackson’s fights. Of Jackson, FDR said: “We look back on his amazing personality, we review his battles because the struggles he went through, the enemies he encountered, the defeats he suffered and the victories he won are part and parcel of the struggles, the enmities, the defeats and the victories of those who have lived in all the generations that have followed.”

Jefferson, too, provided Roosevelt with an inspiring example as the world grew dark in the war years. FDR encouraged the building of the Jefferson Memorial on the Tidal Basin and, the bicentennial of Jefferson’s birth, on April 13, 1943, the president traveled the short distance from the White House to dedicate it. He was not shy about drawing comparisons between Jefferson’s age and his own; and, by implication, between Jefferson and himself, or at least between the tasks which confronted the two men. “Jefferson was no dreamer—for half a century he led his State and his Nation in fact and in deed. I like to think that this was so because he thought in terms of the morrow as well as the day—and this was why he was hated or feared by those who thought in terms of the day and the yesterday.”

Harry and Dick

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Harry Truman was that rarest of creatures: a candid politician. In interviews and private notes after he left the White House, Truman left an unusually rich collection of often-tart judgments about his predecessors—judgments informed, to be sure, by his own experience of human nature and of high office. Of Jackson—another man of the people—Truman said: “He wanted sincerely to look after the little fellow who had no pull, and that’s what a president is supposed to do.”

In private Truman could be—well, he could be Trumanesque. He lauded Washington, Jefferson, Jackson, Lincoln, Polk, Wilson, and FDR. And he hugely admired FDR, but did say that Roosevelt’s “ego, which probably wasn’t too miniscule to start with,” had led him to overreach on the court-packing scheme after the 1936 landslide.

Yet he once called Richard Nixon “a shifty-eyed, goddamn liar, and people know it. I can’t figure out how he came so close to getting elected President in 1960. They say young Kennedy deserves a lot of credit for licking him, but I just can’t see it. I can’t see how the son of a bitch even carried one state.” Of Eisenhower, recalling a visit during the 1952-53 transition, Truman said: “He came to see me. I invited him in not long after the election, and he didn’t want to come; I think he didn’t want to interrupt his golf game down in Florida or Georgia or wherever it was, but he finally did come. And he looked around a little, but I could see that nothing that was said was getting through to him. He got there mad, and he stayed mad. One of his troubles … he wasn’t used to being criticized, and he never did get it through his head that that’s what politics is all about. He was used to getting his ass kissed.”

An Unlikely Bond

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One of the more remarkable scenes in recent presidential history came in the spring of 1994, at the funeral of Richard Nixon, the only man other than Franklin Roosevelt to have been a part of five major-party national tickets in the 20th century. Bill Clinton, a son of the generation that came of political age in reaction to the Watergate scandal that forced Nixon’s resignation in 1974, spoke on behalf of the former presidents in attendance—Gerald Ford, Jimmy Carter, Ronald Reagan, and George H.W. Bush.

As tends to happen in such moments, Clinton found Nixon to be an example of the things Clinton himself wanted for the country. “When he became President, he took on challenges here at home on matters from cancer research to environmental protection, putting the power of the Federal Government where Republicans and Democrats had neglected to put it in the past,” Clinton said. “In foreign policy, he came to the Presidency at a time in our history when Americans were tempted to say we had had enough of the world. Instead, he knew we had to reach out to old friends and old enemies alike. He would not allow America to quit the world.”

The incumbent president made a subtle call for something that all presidents—indeed all people—hope for: that they be seen with a sense of proportion and in a spirit of forbearance. “Oh yes, he knew great controversy amid defeat as well as victory. He made mistakes, and they, like his accomplishments, are part of his life and record. But the enduring lesson of Richard Nixon is that he never gave up being part of the action and passion of his times. He said many times that unless a person has a goal, a new mountain to climb, his spirit will die….Today is a day for his family, his friends, and his nation to remember President Nixon’s life in totality. To them, let us say, may the day of judging President Nixon on anything less than his entire life and career come to a close.”

We don’t often think of the two in the same frame, but Ronald Reagan’s view of JFK is fascinating not least because, as Reagan himself said, he was “for the other fellow” in 1960—Richard Nixon. In Kennedy, Reagan knew a great showman when he saw one. “Many men are great, but few capture the imagination and the spirit of the times. The ones who do are unforgettable,” he said in June 1985, at an endowment fundraiser for the John F. Kennedy Presidential Library. “Four administrations have passed since John Kennedy’s death, five presidents have occupied the Oval Office, and I feel sure that each of them thought of John Kennedy now and then, and his thousand days in the White House.”

Then Reagan let his imagination—that vivid, wonderful imagination—take flight. He went on: “And sometimes I want to say to those who are still in school, and who sometimes think that history is a dry thing that lives in a book: Nothing is ever lost in that great house; some music plays on. I have been told that late at night when the clouds are still and the moon is high, you can just about hear the sound of certain memories brushing by. You can almost hear, if you listen close, the whir of a wheelchair rolling by and the sound of a voice calling out, “And another thing, Eleanor!” Turn down a hall and you can hear the brisk strut of a fellow saying, “Bully! Absolutely ripping!” Walk softly now and you’re drawn to the soft notes of a piano and a brilliant gathering in the East Room, where a crowd surrounds a bright young president who is full of hope and laughter. I don’t know if this is true…but it’s a story I’ve been told. And it’s not a bad one, because it reminds us that history is a living thing that never dies. A life given in service to one’s country is a living thing that never dies.”

The certitudes and constructs of campaigns crumble under the relentless force of the complicated reality of the actual job. As Obama remarked at the unveiling of the George W. Bush portrait in June 2012—after thanking the 43rd president for leaving him an excellent TV sports package—“We may have our differences politically, but the presidency transcends those differences. We all love this country. We all want America to succeed.” On that, at least, let’s hope they—and we—can all agree.

Meacham, a TIME Contributing Editor-at-Large, is a Pulitzer Prize-winning historian. This essay is adapted from a Presidents’ Day lecture Meacham is to deliver at The University of the South in Sewanee, Tennessee, on Monday, Feb. 17.

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