One big difference between Biden and every recent Dem nominee

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.