Scott Morgan / Reuters

When critics say that Joe Biden isn’t progressive enough, they’re mostly referring to his record and positions on policy. But the former vice president’s messaging is literally backward-looking. Biden is running a campaign of restoration—returning the United States to its rightful place before (as he sees it) the current president came onto the scene and trashed the joint.

“If we give Donald Trump eight years in the White House, he will forever and fundamentally alter the character of this nation,” Biden warned in his announcement video.

It’s not just that Biden’s message over the first few days of his campaign has been aimed straight at the #Resistance—though it has, even as other Democratic hopefuls have largely opted against head-on attacks on Trump. Biden is running on open nostalgia. He wants to take the country back, all the way to the dim and distant days of 2015 or so, when the Obama administration he served in ran the country and Trump was merely a punch line.

Appealing to nostalgia is a favorite play for Republican candidates. While Trump’s “Make America great again” slogan makes the return to an imagined past more explicit than most, backward-looking campaigns dovetail neatly with conservatism. But they’re a tougher sell in the Democratic Party. Even before the party’s recent leftward shift, Democratic candidates have tried to strike a balance between praising fundamental principles of the country and offering something new and innovative.

Every successful Democratic candidate of the past half century, as well as several unsuccessful ones, has embraced the idea of forward progress. John F. Kennedy sold voters on his youthful exuberance. Lyndon B. Johnson offered the Great Society. Jimmy Carter was an obscure evangelical governor from the South—about the furthest thing from Richard Nixon or Gerald Ford—who billed himself as an untainted reformer. Bill Clinton heralded a transformed, centrist Democratic Party. Barack Obama promised hope and change. Clinton offered perhaps the most eloquent and memorable formulation of this maneuver in his first inaugural address—a little old, a little new.

“Our democracy must be not only the envy of the world, but the engine of our own renewal,” he said. “There is nothing wrong with America that cannot be cured by what is right with America.”

These days, most Democratic politicians are just as eager for change but less likely to look kindly on the past. Taking a radical view, they are more likely to trace the problems in contemporary American society to long-standing fissures and failures in U.S. history, especially on race, class, and gender. In other words, they believe not that Trump “will forever and fundamentally alter the character of this nation,” but that he’s brought out dark characteristics present since its founding. This strain in present in Bernie Sanders, whose political hero Eugene V. Debs was making systemic critiques of American society a century ago, and it’s present whenever candidates talk about reparations, which are intended to respond to sins of racism that stretch back to even before the United States itself existed. These Democrats also bluntly reject the idea of returning to a golden age.

“I don’t think you can ever have an honest politics that revolves around the word again,Mayor Pete Buttigieg has said. While Buttigieg was clearly taking a swipe at Trump’s slogan, his implication was also that Trump, while perhaps uniquely bad, is more a symptom and an accelerant of what ails America than a cause.

Biden, however, stands against this movement. Where his rivals tend to view Trump as a culmination, Biden sees him as an aberration.

“I believe history will look back on four years of this president and all he embraces as an aberrant moment in time,” he said in his campaign-announcement video. “But if we give Donald Trump eight years in the White House, he will forever and fundamentally alter the character of this nation—who we are—and I cannot stand by and watch that happen.”

If this is true, the trick is to just turn the clock back. Biden made the comparison with Trump explicit with a paraphrase on Good Morning America on Tuesday, promising to “make America moral again.” This restorationist rhetoric, far more than any particular policy idea, has dominated Biden’s first week on the trail.

This approach is quietly radical for the Democratic Party, and it puts Biden on a collision course with politicians like Buttigieg. Yet it would be almost impossible for Biden to do anything else. He can’t run as the youth candidate, and unlike Sanders—or Trump in 2016—he has no claim as an outsider. Biden’s experience is his greatest asset, even if it does seem jarring that the Obama years have so quickly passed into the realm of rose-tinted nostalgia. (And yet how far away those years seem.)

At this early stage, it’s not clear that voters object to Biden’s backwards glance. Biden was already leading the field before his official entry, and he’s seen a polling bump since. A CNN poll released Tuesday found that only one in four Democrats think it’s important that the nominee be an outsider, which is good news for Biden. Two in three think the nominee must represent the future of the Democratic Party—bad news for Biden. But by far the most important criterion for Democratic voters, with 92 percent ranking it extremely or very important, is the ability to beat Trump.

But appeal to nostalgia underscores Biden’s vulnerabilities, too. He has already come in for intense criticism over some of his past policy positions, particularly his opposition to busing to integrate schools, his handling of Anita Hill’s sexual-harassment allegations against now–Supreme Court Justice Clarence Thomas, and his role in the 1990s crime bill. Each of these harkens back to the long-standing flaws that other Democrats see in U.S. society. History is a Pandora’s box: Biden may want to turn attention to the narrow period from 2008 to 2016, but once you reopen the past, other unpleasant things fly out.

Biden hopes to ride his restoration argument to victory in the Democratic primary, but that would represent a surprising break with the party’s other recent nominees. Maybe Biden has cracked the code to 2020, or possibly he’ll discover that those who campaign on the past are doomed to repeat it.

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