Democratic presidential candidate Sen. Bernie Sanders (I-Vt.) (Mike Groll/AP)

James Downie is The Post’s digital opinions editor.

At the end of a bruising presidential primary, it would not have been surprising if Hillary Clinton and the Democratic establishment had stiff-armed progressives who wanted changes to the party’s platform. Yet the draft 2016 version leaked Friday shifts noticeably leftward from its 2012 counterpart in both policy and language. While not yet set in stone, the change is an encouraging sign that activists’ years of work are paying off and that the party is embracing an agenda that speaks to the concerns of millions of Americans who have too often been forgotten in mainstream political debate.

From the opening of the 2016 draft platform, one can see the rhetorical fingerprints of progressive movements, especially Black Lives Matter and the insurgent presidential campaign of Sen. Bernie Sanders (I-Vt.). In the preamble, the authors warn that “as working people struggle, the top one percent accrues more wealth and more power” and “our nation’s long struggle with race is far from over.” Though the 2012 platform repeatedly criticized inequality and — to a lesser extent — discrimination, it had none of the stridency of the 2016 draft version. “The greed, recklessness and illegal behavior on Wall Street must be brought to an end,” it declares. (Can you imagine the New Democrats of the 1990s putting illegal behavior and Wall Street in the same sentence?) Later, the authors promise that the party “will push for a societal transformation to make it clear that black lives matter.” Not too long ago, more politically cautious Democrats would have steered clear of phrases like that, but here they are.

The changes go beyond rhetoric to genuine policy differences. The 2012 platform, when discussing helping the middle class, centered on extending tax cuts. Although the party included a sentence calling for a higher minimum wage, it did not specify a target. The 2016 draft drops the tax cuts for a minimum wage increase to “at least $15 an hour,” undoubtedly a nod to the “Fight for 15” movement embraced by Sanders.

Similarly, the new platform endorses specific reforms of the criminal justice system — closing private prisons, giving police training in conflict de-escalation and body cameras, “banning the box,” prioritizing “treatment over incarceration in tackling addiction” and so on — all new in 2016. And for the first time, the Democratic platform calls for abolishing the death penalty. The party has traveled a long way from Bill Clinton returning to Arkansas mid-campaign for the execution of Ricky Ray Rector.

Even President Obama’s signature piece of legislation, the Affordable Care Act, is overtaken by the shift to the left. The 2012 platform was understandably content to focus on the law’s successes; with Hillary Clinton’s determination to benefit from Obama’s legacy, the 2016 version might be expected to do the same. Yet the drafters go much further, declaring that “Americans should be able to access public coverage through Medicare or a public option.” It is extraordinary that Democrats are saying that the most popular figure in the party’s biggest accomplishment is not liberal enough.

There are other victories for progressives and activists throughout the draft, such as a prohibition on Wall Street firms choosing which credit agency rates their products and support for postal banking for low-income Americans. Progressives did not win every fight; there is no call for a ban on fracking or opposition to the Trans-Pacific Partnership trade deal. Given that Obama opposes both stances, any hope for victory on those issues was always naive. But overall, this would be the most progressive Democratic platform in history.

The obvious argument against making too much of these changes is that party platforms are non-binding and therefore signify nothing. This misses the point: Platforms reflect parties’ trajectories. In 1976, only a few years after Roe v. Wade, the two partiesplatforms each recognized both the pro-life and pro-choice sides. Not until the 1980s, after Democrats and Republicans had hardened their positions, did the platforms take unequivocal stances. (This year’s Democratic platform, in fact, is the first to call for the repeal of the Hyde amendment limiting the use of federal money for abortions.) The 2016 Democratic draft reflects a far more progressive party than even four years ago.

The Democratic platform’s leftward turn vindicates the continuing campaigns of Sanders, Black Lives Matter and other progressive groups. Critics predicted that a refusal to quiet criticisms of the party establishment would reduce activists’ leverage as the convention neared. Instead, activists’ work has produced notable victories and shifted the center of the political conversation.

Those victories are also good for the Democratic Party. Too often in the past, the interests of minorities, the poor and others have been either ignored or barely acknowledged in the party’s platform. But the version being prepared for 2016 suggests Democrats are starting to take their interests seriously, and that can only be a good thing for the country.