Jeff Weaver, a long-time aide to Senator Bernie Sanders and campaign manager for Sanders' 2016 presidential campaign, is a leader of "Future to Believe In (FTBI) PAC," a new political group to support Democratic presidential candidate Joe Biden and push for more progressive policies. The opinions expressed here are the writer's own. Read more opinion articles at CNN.

(CNN) As progressives debate their role in the upcoming general election, they must consider what our movement has accomplished in a very short time and why, at this moment, we must press our advantage and not abandon the people we represent -- working people, middle-income people, the poor and marginalized communities.

Jeff Weaver

Bernie Sanders' millions of volunteers, supporters, donors and voters demonstrated the breadth of our movement that is widening the boundaries of acceptable political debate in this country. As Bernie himself has pointed out, ideas like Medicare for All and jobs for all, that only a few years ago would have been radical, are now supported by the American people. Our work has been so successful that policies such as a $15 minimum hourly wage and free public college tuition have been adopted by the Democratic Party and even by Bernie's primary opponents.

We made that happen. We made policies that benefit everyday people important again. We effectively delivered, and will continue to deliver, a new hopeful vision for our country. My good friend Senator Nina Turner uses a quote from the late Congresswoman Barbara Jordan that sums up the vision that we offer -- "an America as good as its promise."

The Sanders' candidacy was always about accelerating our path toward that "America as good as its promise" by institutionalizing as much progressive change into law as could be accomplished had he become president. Just as Republicans have spent decades unsuccessfully trying to gut Social Security and Medicare, so they would spend decades trying to undo a President Sanders' plans for college for all, Medicare for All, and the rest.

Now we have come to the place where Bernie is not going to be the president. I wish I could convey how deeply that hurts me to write it. But that's where we are. We can spend a lot of time fixated on the unfairness of the process over the last two primary cycles, the role of big money, the advantages of the establishment and the fecklessness of much of the media. All that is true. But, so what? Who in our movement ever thought that the ruling class was just going to roll over? Progressive politics is not for the faint of heart.

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