The hollowing out of the American economy and the trauma of Trump have generated a mini-boom for American socialism. Just look at the Democratic Socialists for America as they gather this weekend for their annual convention. The ranks of DSA have never been larger. Eight-hundred delegates are expected at the University of Illinois-Chicago campus, more than four times as many as attended the group’s last get-together in 2015.

Three years ago DSA had 6,500 members. Now it has 24,000, 1,000 of them joining in a single day after Trump was elected president. The group boasts 150 chapters in 48 states and is growing fastest in small cities and rural areas.

“We are the largest socialist organization in America since the Henry Wallace campaign” of 1948,” says Joseph Schwartz, a member of the DSA national board and political science professor at Temple University.

The resurgent DSA is one of the most long-lived organizations among the constellation of groups seeking to build a leftist movement that can check and challenge the most reactionary government in Washington since the Civil War. Like MoveOn, Our Revolution, Indivisible, Swing Left and others, DSA seeks to pull the national Democratic Party to the left without actually joining the Democratic National Committee.

The group was founded in 1974 as the Democratic Socialist Organizing Committee, led by Michael Harrington, a tireless intellectual best known for his 1962 best-selling book about Appalachian poverty, The Other America. Among DSA's most famous members are public intellectuals Cornel West and Barbara Ehrenreich.

DSA offers what the other left activist groups do not: a generous serving of the S word.

“Socialism” is the antidote to the pallid pro-business message that doomed Hillary Clinton to a humiliating defeat. It's a most efficient way to say, “I’m dead serious about change.”

“DSA puts the focus on who controls the wealth of society,” Schwartz said in a phone interview. “You can’t have political democracy without economic democracy. You can’t fight racism without economic democracy. Other people talk about reining in corporate power. We talk about social ownership.”

That militance is part of DSA’s growing appeal.

“You could call it the revolt of baristas,” says Schwartz. “Our fastest growth is among college-educated but not highly privileged young people. They who have high social capital, but who are underemployed, they can see this economy doesn’t offer them a future, and tinkering with it isn’t going to help.”

In DSA’s platform, “Resistance Rising: Socialist Strategy in Age of Revolution," the group lays outs its priority for building an anti-capitalist politics via multiracial and intersectional coalitions and community and labor organizing.

At the same time, DSA generally takes the un-radical path of working within the Democratic Party, seeking to transform it from the inside, rather than overthrow it from the outside. While some DSAers want to see the creation of a new labor party, “most are pragmatic about using the Democratic Party ballot,” Schwartz says.

For a party languishing in a historic nadir, DSA provides a preview of a possible future. The convention will set DSA’s priorities for the next two years, which dovetail with the needs of a national party in need of resuscitation.

The Democrats are groping for a message. Nancy Pelosi and Chuck Schumer came up with “A Better Deal,” emphasizing jobs, a point on which polls show the party is extraordinarily weak. DSA has a more focused and ambitious message: “Medicare for all,” a single-payer system that establishes health care as a universal social right.

The national party, top heavy with consultants and corporate money, needs to change its message and build a credible activist base with local roots to sell its message door to door. DSA has that. “Unlike the DNC, we have a 50-state strategy,” says Schwartz. The DSA delegates will consider plans to rebuild alliances with organized labor via non-traditional forms of organizing.

Finally, the Democrats need new blood, especially at the state and local level where DSA seeks to cultivate a farm team of viable socialist electoral candidates. DSA claims 16 members are now serving in elected positions around the country. This may be the most valuable service of DSA: producing a generation of homegrown leaders with the outside/in appeal of a Bernie Sanders.

The resurgence of DSA in hard economic times vindicates the socialist truism that "class really matters," says Michael Kazin, historian of the American left and DSA member. Nonetheless, he notes that while the group is flourishing, it is still not large by historical standards. In 1912, he notes, the Socialist Party had 120,000 members and exercised a gravitational pull on the two-party system, legitimizing radical causes like labor rights, women's suffrage, and opposition to World War I for the major parties.

Whether the Sanderista left achieve such influence in the age of Trump remains to be seen. But without the anchor of radical organizations like DSA rooted in every state, the progressive movement and the Democratic Party will remain adrift in the face of an increasingly authoritarian regime in Washington.

“If you don’t build an independent socialist movement,” says Schwartz, “the whole progressive movement becomes weaker, more milquetoast.”