The Democratic establishment was shocked—and in some cases appalled—by Bernie Sanders’s insurgent bid for president last year. How could 12 million primary voters cast ballots not for market-friendly progressivism or New Deal liberalism, but democratic socialism? And against a Clinton, no less? But astonishment eventually gave way to acceptance, even implicitly from the nominee herself: the success of Sanders’s campaign was no fluke, proving that the Democratic Party had moved decisively to the left.

But 2016 was not the year the party became more progressive. It was merely when the establishment Democrats realized it had moved. Many observers recognized a shift underway years earlier. In 2013, in a New Republic article titled “Hillary’s Nightmare? A Democratic Party That Realizes Its Soul Lies With Elizabeth Warren,” Noam Scheiber accurately predicted the rift exposed by last year’s primary, arguing that it would “cut to the very core of the party” in the next race for the White House:

Sanders won the support of the first, ascendant side of that divide. That would seem to to put the Vermont senator in a position to be the party’s new standard-bearer—especially given that, according to recent polling, he’s the most popular politician in the country. But he has returned to the Senate as an independent rather than a Democrat, aiming to “transform the Democratic Party” from the outside; what’s more, he’s 76 years old. This power vacuum has provided a clear opening for a new, progressive leader of the party—and she’s primed to occupy that role just as Scheiber foresaw, albeit a little later than he suggested. “We are not the gatecrashers of today’s Democratic Party,” Warren told Netroots Nation this year. “We are not a wing of today’s Democratic Party. We are the heart and soul of today’s Democratic Party.”

The 68-year-old Massachusetts senator is right—and she’s not the only one who says so. Amy Walter, the national editor for the Cook Political Report, wrote last week that “it’s going to be very difficult for a Democrat to win the nomination of his/her party on anything but the Warren platform.” Walter cited Pew Research data showing that “Democrats have moved dramatically leftward since the 1990s on issues like the social safety net, immigration, and race relations. On those issues, the so-called Warren wing represents the mainstream of Democratic opinion.” Congressman Jamie Raskin, vice chair of Congressional Progressive Caucus, told me Warren “does define the center of gravity within the Democratic Party.” Even the center-left Brookings Institution scholar Bill Galston, who disagrees with Warren on many policies, acknowledged her ascendancy in this moment. “If you forced me to lay down a bet today on the most likely nominee of the Democratic Party, it would be Senator Warren,” he said—while emphasizing that this was “a simple assessment of current realities,” not a prediction. “If you asked me to define the center of gravity, it would be pretty close to where she is right now.”

This reality has major implications for the future of the party—in next year’s 2018 midterms, the 2020 presidential election, and beyond. If Warren is now the soul of the Democratic Party, what will this transformed party look like and what will it fight for?

