Bernie Sanders’ historic presidential run proved decisively that a powerful electoral campaign can be built without corporate money, based squarely on the interests of the 99%. Hundreds of thousands of supporters turned out for Sanders’ massive rallies, and many young people and working-class people became politically active for the first time.

Yet, since his endorsement of Hillary Clinton and her nomination at the Democratic National Convention, Sanders has gone from super-rallies to struggling to gather more than one or two hundred people to drum up enthusiasm for her Wall-Street-backed candidacy.

“Our Revolution,” the organization launched to harness Bernie’s volunteers and supporters into a nationwide political movement, didn’t get past the starting gate before the majority of its staff had quit. The exodus was sparked by the choice of Jeff Weaver, Sanders’ former campaign manager, as director – with objections to his campaign leadership, relationship to the Democratic establishment, and his alleged desire to court wealthy donors. Instead of calling for the continuation of Bernie’s political revolution against the billionaire class, Our Revolution echoes the Clinton campaign, asking supporters to “let me know you will stand with me to defeat Donald Trump.”

While horrified by Trump, Sanders’ supporters are not excited about Clinton or her pro-corporate policies and are turned off by Bernie’s about-face. Tensions have continued to develop within the Democratic Party. In a number of primary races, the Democratic Party establishment opted to endorse or run neoliberal candidates against Berniecrats. Clinton’s campaign has shown little interest in trying to convince Sanders’ supporters and, instead, boldly chases Republican voters and money. While most will hold their noses and vote for Clinton in the general election, increasingly, many former Sanders supporters are recognizing the futility of attempts to reform the Democratic Party.

At the same time, some Sanders activists have to taken the “Bern” to new causes, such as the Standing Rock protests in defense of indigenous treaty rights and against the exacerbation of climate change. During his campaign, Bernie met with members of Native American tribes and highlighted the shameful relationship between the U.S. government and native people. And, while Sanders has spoken out against the Dakota Access Pipeline, his support for the NO-DAPL movement is contradicted by his support for Clinton. Clinton’s silence on the subject has been deafening – in spite of the historic importance of the movement, the urgency of the climate crisis, and even the brutal response against protesters and journalists, including arrest warrants and the use of attack dogs.

Trying to advance a political revolution against the billionaire class inside of a counterrevolutionary institution such as the Democratic Party is a failed strategy. Mass social movements are what change society. If we want to win what Bernie Sanders campaigned for, it’s up to us to lead the way in building our own movements and our own political party – of, by, and for the 99%.