For the past several months—and the past three Democratic presidential debates—the party’s two progressive standard-​bearers, Bernie Sanders and Elizabeth Warren, have been making love, not war. As Warren told Anderson Cooper in the first debate, “Bernie and I have been friends forever.” During the second debate, with both of them on the stage the same night, Warren made a point about the disastrous effects of US trade policy—and Sanders chimed in, saying, “Elizabeth is absolutely right.” When Wyoming Representative Liz Cheney attacked Warren on security policy, Sanders tweeted in the Massachusetts senator’s defense, while Warren has resolutely refused repeated media entreaties to disavow her support for Medicare for All, the Vermont senator’s signature initiative.1

This absence of infighting on the left—or at least between these two left candidates, since elsewhere on the left the narcissism of small differences rages unabated—has long troubled the centrist press. New York magazine’s “Intelligencer” reported the truce between Sanders and Warren was breaking down in June; Politico speculated the two were drifting apart in July; The Hill posted a hopeful report of imminent hostilities in August. In September, only a few hours after the Working Families Party announced it was endorsing Warren, she spoke in front of more than 20,000 people in New York’s Washington Square Park—the very spot where Sanders, backed by Vampire Weekend, drew a huge crowd in April 2016. Of course, that was also the year Sanders described the WFP as “the closest thing there is to a political party that believes in my vision of democratic socialism.”2

Does the WFP endorsement mean the cool kids have abandoned Sanders for Warren? Has the American left’s long-awaited—by our enemies—internecine bloodletting finally begun? Is the WFP endorsement evidence of that organization’s decline? Or the abandonment by the WFP leadership of any claim to democracy or socialism? Is a partnership that Elle once called “the Jim and Pam of the Democratic race” irretrievably on the rocks?3

Some people seem to think so. Our comrades at Jacobin were quick to hurl anathemas at the WFP and Warren, dismissing her as the “darling of a particular strata of more affluent liberal progressives.” Online, predictably, the pileup soon turned ugly, with WFP leaders Maurice Mitchell and Nelini Stamp becoming the targets of racist abuse, according to an open letter posted on Medium by Black Lives Matter cofounder Alicia Garza and signed by over 100 other black leaders.4

Sanders immediately condemned any attempt to harass or bully the WFP leaders. In the immediate aftermath of the endorsement—which must have come as a disappointment to Sanders—his campaign manager, Faiz Shakir, declared, “We look forward to working with the Working Families Party and other allies to defeat Donald Trump. Together, we’ll build a movement across the country to transform our economy to finally work for the working class of this country.”5

Surely that must be right. However much some on Team Sanders or Team Warren might be spoiling for a fight, their two principals have shown little inclination to turn on each other. Not while Trump is still in the White House. Or while Joe Biden—whose record on issues ranging from bankruptcy to busing to the invasion of Iraq to trade policy makes him a uniquely weak challenger to Trump, even without his unfortunate habit of tripping over his own tongue—remains the Democratic front-runner.6

Because the truth is that plenty of progressives like both candidates. Politics may indeed, as Nation contributor Jeffrey C. Isaac recently argued, be “all about choice.” Certainly the WFP has every right to make its preference clear—or at least the preference of a majority under a ranked-choice vote that also gave the party’s national leadership equal weight with members and supporters. And Sanders supporters have every right to highlight that mechanism (though their criticism would have more heft if they held groups that endorsed Sanders, like the Democratic Socialists of America and the electrical workers’ union, to the same standard).7

But do the rest of us really have to choose? Already? Working together, Sanders and Warren have been incredibly effective not just in making the case for Medicare for All, a Green New Deal, and all the other issues that are common ground for them but also in dramatically widening the entire left lane of American politics. Thanks to Sanders’s political courage and consistency and Warren’s skillful, steady push at the boundaries of political possibility, ideas once dismissed as radical now dominate the Democratic debates. Sure, Warren calls herself a “capitalist to my bones.” And after deluding ourselves over Barack Obama’s supposed secret radicalism, we’d better believe her. Her supporters wonder, “Is America ready to elect a socialist?” There’s only one way to find out.8

Nearly a year ago, The Nation argued for the importance of the “ideas primary,” which would offer “reformers, activists, and grassroots groups their best opportunity to have an impact on the political debate.” And so it has.9

At some point, we probably will have to choose. The Iowa caucuses in early February should help clarify matters, and the New Hampshire primary the following week is a test of strength both Sanders and Warren need to win. Until then, though, we hope the two candidates maintain their truce, competing to outdo each other in the boldness of their ideas and the breadth and passion of their support—but also continuing to have each other’s backs.10

This country has never been in greater need of bold progressive leadership. Or, arguably, been more open to radical solutions to the problems we face. Warren and Sanders show every sign of knowing that. And of knowing something else their supporters might bear in mind: Solidarity begins at home.11