democratic socialists of america parade
CNN  — 

On Tuesday afternoon, as Illinois Rep. Luis Gutierrez announced his retirement plans and endorsed Cook County Commissioner Chuy Garcia in the coming Democratic primary, the country’s largest socialist organization was mobilizing behind a candidate of their own.

Chicago Alderman Carlos Ramirez-Rosa, a Democrat and member of the Democratic Socialists of America, jumped into the contest right alongside Garcia, kicking off a race that could vault a new crop of ambitious leftists – DSA’s dues paying membership jumped to more than 31,000 from about 5,000 over the past year – into mainstream political prominence.

What comes next will be a step up in class — and a stress test for the growing movement. DSA-backed candidates scored a series of victories earlier this month, most notably in Virginia, where Lee Carter defeated Jackson Miller, the Republican majority whip in the House of Delegates. But Garcia, who supported Sen. Bernie Sanders early on in the 2016 Democratic primary cycle (after Sanders backed his bid to oust Chicago Mayor Rahm Emanuel), is a well-credentialed progressive.

“They’re both really strong candidates, so what Carlos needs to do is articulate why his vision, and a vision for democratic socialism, really needs a voice in Washington that it lacks right now,” said David Duhalde, DSA’s deputy director. That means convincing voters that Ramirez-Rosa “would be better to represent not only the people from his district, but the people of the United States by representing a unique viewpoint that’s sorely missing (in the House) since Sanders went to the Senate in 2006.”

Overnight, as rumors spread that Gutierrez would reverse course and stand down, and Ramirez-Rosa told CNN he planned to “begin circulating (paperwork) tomorrow” if the seat came open, DSA members online reacted joyously – “folks are pumped,” Ramirez-Rosa noted drily in a text – and began to bubble with plans to organize behind his campaign.

In a statement early Tuesday morning, Ramirez-Rosa made note of his time working as a staffer for Gutierrez, then laid out his platform, a pledge to “vigorously oppose President Trump’s regime, and fight for the progressive policies that will uplift the 4th District’s working families, including medicare for all, free college tuition, stopping deportations, and a $15 living wage.”

DSA is not a political party and does not make donations to candidates. It hasn’t yet formally endorsed Ramirez-Rosa, though its support should become official in the coming days. Members are already working alongside the candidate as he hustles to collect the requisite signatures to assure his place on the ballot. The test will come as the race enters the new year – the primary is March 20 – and DSA’s activist core is called on to mobilize voters.

On the ground in Chicago, there is an early sense of confidence among organizers close to Ramirez-Rosa. They are counting on a surge of support from allies around the country, and betting that DSA’s swarming and insistent social media presence – if you’ve spent an hour on Twitter in the last 12 months, you’ve seen their rose emoji emblem next to users’ handles – will amplify his and their message.

“There’s a lot of people here who already have the skills and the talents. We’re all essentially organizers. That’s what we do. So it’s about putting out the rose signal and saying yeah, we’re ready,” Chicago DSA’s Lucie Macías said hours before Gutierrez made his announcement. By then, Macías said she had already been swamped by members from in and outside the city hoping to volunteer on behalf of the campaign.

Despite the excitement among activists, Ramirez-Rosa begins the race as a clear underdog. Separating himself from Garcia will be its own trial. Gutierrez in his remarks Tuesday made note of Garcia’s close to ties to Sanders, suggesting he had a direct line to the senator, who had introduced a new recovery package for Puerto Rico earlier in the day. Garcia said his candidacy would “(build) on the legacy of (former Chicago) Mayor Harold Washington, the foresight and energy that brought young people together for Sen. Bernie Sanders and the work of Rep. Gutierrez.”

Sanders’ office did not respond to an email asking if he planned to endorse in the race.

The ties between Sanders and Garcia underline another challenge facing DSA – whether it can favorably definite itself against competition that looks similar at a glance.

“Chuy has always been a good guy on our issues – it’s a real win-win for progressives,” Duhalde said. But in sorting out the candidates’ relatively narrow differences, the organization has a unique opportunity to highlight its leftist political agenda – and test its electoral muscle.

“One of the counter-narratives to DSA’s recent success on election day was that anyone running as a Democrat or against the Trump agenda would have won,” Duhalde said. “Carlos is a more challenging test. Can DSA actually help people get elected or make a huge difference in their campaign, aside from just the anti-Trump message?”

With less than a week until the filing deadline and only a few months before voters head to the primary polls, the answer isn’t far off.