Throughout most of the 2016 presidential primaries, the media focused on the noisy and reactionary rift among Republicans. Until the battle between Hillary Clinton and Bernie Sanders turned acrimonious in the home stretch, far less attention was paid to the equally momentous divisions within the Democratic Party. The Clinton-Sanders race wasn’t just about two candidates; instead, it underscored a series of deep and growing fissures among Democrats, along a wide range of complex fault lines—from age and race to gender and ideology. And these disagreements won’t fade with a gracious bow-out from Sanders, or a victory in November over Donald Trump. For all the talk of the Democrats’ need for “unity,” it would be a serious mistake to paper over the differences that came to the fore in this year’s primaries. More than ten million Democrats turned out in force this year to reject the party establishment’s cautious centrism and cozy relationship with Wall Street. Unless Democrats heed that message, they will miss a historic opportunity to forge a broad-based and lasting liberal majority.

To help make sense of what’s causing the split, and where it’s headed, we turned to 23 leading historians, political scientists, pollsters, artists, and activists. Taken together, their insights reinforce the need for a truly inclusive and vigorous debate over the party’s future. “There can be no settlement of a great cause without discussion,” observed William Jennings Bryan, the original Democratic populist insurgent. “And people will not discuss a cause until their attention is drawn to it.”

It’s Hillary’s fault for lowering our hopes

Ron Haviv / VII for the New Republic

John Judis, former senior editor at The New Republic and co-author of The Emerging Democratic Majority: In 1984, you had Walter Mondale, a candidate of the Democratic establishment, pitted against a young upstart, Gary Hart. The split wasn’t left-right—it was young-old, energetic-tired, vision-pragmatism. Bernie, for all his 74 years, represents something still of the rebellious Sixties that appeals to young voters, while Hillary represents a tired incrementalism—utterly uninspiring and rooted largely in identity politics and special interest groups, rather than in any vision for the future.

Democrats have neglected white workers

David Simon: There’s certainly something unique about this moment, and the populist rebellion that has affected both the Republican and Democratic parties. And I think it’s earned. Both parties can be rightly accused, not to the same degree, of having ignored and abandoned the working class and the middle-middle class for the past 30 years.

Don’t worry: Trump will unite us

Mark Peterson / Redux

John Judis: Whatever shortcomings Clinton’s campaign has in creating unity are likely to be overcome by the specter of a Trump America.

Ruy Teixeira: I don’t see the people who support Sanders, particularly the young people, as being radically different from the Clinton folks in terms of what they support. They’ll wind up voting for Hillary when she runs against Trump.

David Simon: If you’re asking me if I think the Democratic Party will heal in the general election, I think it will. Trump helps that a lot. The risks of folding your arms and walking away are fundamental, in a way they might not be with a more viable and coherent candidate. But let’s face it, the idea of this man at the helm of the republic is some scary shit.

It’s a trap!

Astra Taylor: The young thing, this millennial left turn, is great. But there’s a part of me that’s afraid. In the 1960s, the story was the counterculture and the new left. It was Students for a Democratic Society, the civil rights movement, the war in Vietnam. But there’s been a lot of smart revisionist scholarship that says the story of the ’60s was not the new left, it was actually the new right, which spent the decade laying the groundwork for its resurgence. At this moment, when left-wing millennials are getting a lot of attention, my fear is that there’s a conservative counterpoint that I’m just not seeing, because we’re all in our little social and political bubbles. We should study the split between the new left and the new right in the ’60s, and make sure that history doesn’t repeat itself.

COVER REFERENCE PHOTOS: JAMIE MCCARTHY/GETTY (SANDERS). MANUEL BALCE CENETA/AP (CLINTON)