Older members of the socialist organization were amazed to see the massive attendance at the convention this year. Now, they need to figure out how to harness it all.

In 1973, Jack Clark met with about 20 or so like-minded socialists in a hotel on the Upper West Side of New York to decide what they wanted to do about the existing framework of socialist parties in American politics.

Forty-four years later, he was sitting in the rafters of the University of Illinois in Chicago forum looking down on a packed convention floor of closer to a thousand Democratic Socialists of America.

The organization has undergone a massive growth spurt since the 2016 presidential election, ballooning to 25,000 national members including an influx of young people devoting themselves to organizing and politics, in some cases, for the first time in their lives.

With that growth has come a challenge many DSA members have never faced before: what to do with actual political prominence and relevance.

“There’s an awful lot of positive energy here, people just feel good about being in a room with so many other people,” 68-year-old Jack Clark, the first national press secretary for the Democratic Socialist Organizing Committee, told The Daily Beast. “None of us have been in a room with 700 active Democratic Socialists who represent people back home. This is just a new experience, I think, for everybody.”

DSA has rich political roots in America, going all the way back to the rise of the labor movement. But in the post-Trump-election word, it finds itself more involved and influential than at any other point in its recent history. The group is organizing from the ground up, applying pressure on national and local politicians, making policy inroads in states, all while providing an outlet separate and apart from the traditional two-party system.