Bernie Sanders’s quest for the Democratic presidential nomination was one of the biggest surprises of the 2016 campaign, surpassed only by the election’s ultimate winner. The rumpled septuagenarian socialist senator from the tiny state of Vermont, who had never even run for office as a Democrat before, went from decades of laboring in obscurity to competing with Hillary Clinton on something approaching even terms. On Tuesday he announced he wants to try again, this time in a race with no obvious frontrunner.

The closest parallel to Sanders’s success was probably Ron Paul: elderly, ideological veteran lawmakers who were beloved by younger voters inside the major political party to which they were intermittently attached (Paul was the 1988 Libertarian Party nominee for president, Sanders technically won all his elections as an independent or third-party candidate) when they sought its presidential nomination late in their careers. Despite their vast differences on economics, both men also wanted an end to perpetual war in the Middle East.

Yet Sanders thrived in a two-way race and came closer than Paul to the nomination, even if he never quite threatened to pull off a Barack Obama-style upset against Clinton. With the GOP’s small government wing in decline, Sanders also appears for now to have had more of a transformative effect on the Democratic Party. “Socialism” is no longer an epithet in American politics and Sanders proved there was valuable ground to the left of Obama.

Can Sanders do it again? To get a sense of how the Bernie revolution might eat its own, let’s reflect on why he fell short the first time. Sanders is an old-school leftist who believes in the centrality of class, not race. Hailing from one of the whitest states in the country, he never made inroads in the communities of color that have become such a large part of the Democratic primary electorate—and the crucial reason Obama prevailed where Sanders’ fellow Vermonter Howard Dean did not.

Sanders was pilloried for his refusal to support open borders in a 2015 interview with liberal pundit Ezra Klein. “No, that’s a Koch brothers proposal,” Sanders replied, later calling it “right-wing.” He added, “It would make everybody in America poorer—you’re doing away with the concept of a nation state, and I don’t think there’s any country in the world that believes in that.” Klein’s website then ran a piece with a headline claiming “Bernie Sanders’s fear of immigrant labor is ugly—and wrongheaded.”

This left-wing economic nationalism might make Sanders attractive to the white working-class voters who cast the decisive ballots for Donald Trump in 2016. So too would the fact that while Sanders is reliably liberal on social issues, including the obligatory support for abortion on demand, he is clearly not animated by them. The key swing voters in Pennsylvania, Michigan, and Wisconsin are economically liberal but socially conservative.

What might be assets in the general election against Trump are huge liabilities in the Democratic primaries, however. In an American progressivism increasingly defined by intersectionality and identity politics, even a socialist who honeymooned in the Soviet Union is something of a relic. Centrists and liberals alike lobbed accusations of sexism against the “Bernie bros” supporting Sanders.

Now these Sanders critics will have liberal women—in some cases, women of color—to choose from in the primaries. Even outside presidential politics, Alexandria Ocasio-Cortez offers the same democratic socialism in a more attractive, internet-savvy, diverse, and woke package. In the primaries, Sanders will have to share the left lane with others. Elizabeth Warren can compete with him on economics, Tulsi Gabbard for antiwar street cred. Nearly all the contenders now support “Medicare for All,” with many signing up for the $42 trillion Green New Deal.

If Democrats decide they want an aging white male for old times sake, Joe Biden could do the trick. His eight years as vice president under Obama revived his political fortunes, as Trump says in less flattering terms. A crowded group of progressives could give an establishment icon who starts with high name recognition a path to the nomination. And Biden could also vie with Trump for blue-collar white voters.

Of course, Biden would be making much of that appeal on the basis of personality. Trump and Sanders rail against bad trade deals and the Iraq war. Biden has an even longer record of supporting such policies than Clinton did. Some of the other Sanders alternatives’ progressivism is of more recent vintage (Kamala Harris) and perhaps of questionable sincerity (Cory Booker). Bernie is a true believer.

But the modern Democratic Party is like a parade marching leftward so rapidly that it is hard for anyone, even Bernie Sanders, to keep up for long.

W. James Antle III is editor of The American Conservative.