New York (CNN) The first time Bernie Sanders came on her radar, back in 2015, she was working as a waitress in downtown Manhattan, uninsured and trying to get by on "less than a living wage."

Four years later, on a stage across the East River in Queens, Rep. Alexandria Ocasio-Cortez stood beside the man she called "Tío Bernie," their hands clasped and raised in triumph, after she delivered him one of the most sought-after endorsements of the Democratic presidential primary -- her own.

"The only reason that I had any hope in launching a long-shot campaign for Congress," Ocasio-Cortez told the massive crowd , "is because Bernie Sanders proved that you can run a grassroots campaign and win in an America where we almost thought it was impossible."

As this coming year's nominating contest swirls into view, Sanders, the resilient democratic socialist from Vermont, will be counting on the support of Latinos, a kaleidoscopically diverse voting bloc that could swing races in states like California, Nevada, Florida and even Iowa, to help him -- and the progressive movement he stoked four years ago -- deliver the "political revolution" his supporters, staffers and volunteers have worked for so long to realize.

An early foothold

Recent polling suggests that Sanders has a clear advantage with young Latino voters, who could, with even a modest growth in turnout, fundamentally alter the composition -- racially and ideologically -- of the Democratic electorate. A Fox News survey out of Nevada last month showcased the base of Sanders' strength. Nearly a third of Hispanics polled, 31%, backed the Vermont independent, giving him a 7-point edge over his closest competitor, former Vice President Joe Biden. Only Massachusetts Sen. Elizabeth Warren, at 10%, reached double-digits. Sanders also led among young voters across ethnic lines, with 34%, twice the total for Biden and Warren, respectively.

In interviews with leading Democratic Latino strategists, pollsters, activists and Sanders' highest-profile backer, Ocasio-Cortez, a common thread emerged: Sanders, bolstered by notable early investments in Latino outreach and underscored by more nuanced messaging than typically directed at this diverse community, has created a growing sense that he might not only win with the community in states like Nevada and California, but chart out a new path for how Democrats seek and earn Latino support.

Still, many of the same observers warned that the Sanders campaign's ambitions are staked on a strategy that demands a break from historical convention -- drawing out young voters. The median age for Latinos in the US today is only about 28 years old, which offers the campaign some reason for optimism. But if Sanders fails, he wouldn't be the first. Since the voting age was reduced to 18 from 21 in 1971, the "youth vote" has repeatedly tantalized liberal campaigns, only to see it underperform relative to their parents' on Election Day.

In its efforts to break that circuit, Sanders' team has made significant new investments and gestures to the Latino electorate.

Chuck Rocha, a senior Sanders adviser, said the proof was plain to see. He ticked off the headlines: The campaign opened its first Nevada field office in East Las Vegas, home to the highest concentration of Latinos in the state; The first dollars Sanders spent in California were used to open an office in East L.A.; And the first thing the campaign did in Iowa was communicate with voters in a bilingual format.

"We started having these conversations early," he said.

Rocha also touted the diversity within Sanders' Latino staff -- which number around 80 at every level, according to the campaign, including its national political director, Analilia Mejia. Carmen Yulín Cruz, the mayor San Juan, Puerto Rico, is one of his campaign co-chairs. The makeup of the team, he suggested, allowed it to avoid some common missteps, like focusing on immigration, despite its importance across the board, at the expense of issues like education and health care, or pushing a one-size-fits-all messaging campaign.

After naming high-ranking Latino staff, including himself, Rocha pointed to their disparate backgrounds.

"We're all from different sections of the Latino electorate, but on the voter file, we still show up as just Latino," he said. "Because of that, we understand the difference between a Latino in Des Moines, where I am today, and a Latino in Miami, and a Latino in San Antonio or L.A. or in South Carolina."

Though Nevada and California are widely regarded as the first real test of a Democratic primary candidate's Latino support, the Sanders campaign is also make a bet on the growing community in Iowa. According to the State Data Center of Iowa, Latinos made up 6.2% of population in 2018, an increase of more than 135% from 2000. The median age was 24 years old and an overwhelming majority were of Mexican, Puerto Rican or Central American origin.

"Latinos in Iowa have the opportunity to seriously shift a race like this. Especially when we're looking at what some people think is a three-way, four-way, dead heat race," Sanders' Iowa state director Misty Rebik told CNN. "If you can turn out Latinos, I don't know, 2% more than we did last time, we win."

Ocasio-Cortez, whose first early state travel with Sanders took her to Iowa, does not hold an official title with the campaign, but her decision to endorse in October was cited by multiple sources who spoke for this story as a "validating" force that, as LULAC national president Domingo Garcia put it, "gave him 'barrio cred' in the community."

"If she's endorsing him," said Garcia, who personally backed Sanders in 2016, "then there must be something good about 'Tío Bernie.'"

Speaking to CNN, Ocasio-Cortez said her decision to use the term, which popped up at times during his first presidential campaign, "is a natural expression of our relationship and how I feel about him."

"In Spanish, 'tíos' are not just blood relatives," she explained. "It's not just the actual sister of your parents, but 'tíos' and 'tías' in Spanish and Spanish culture are people very close to you or close to your family that look out for you, that we look out for each other."

Sanders, Ocasio-Cortez added, had done that for her as she sought to make sense -- and use -- of her growing power.

"Especially in my coming into politics, Bernie's very much been that for me in terms of providing guidance and counsel on how to navigate issues, in how to build a movement," she said. "And it's also a discussion about how we need to be with each other in order to create a larger movement overall."

During her Iowa debut about a month ago, Sanders acknowledged that some might view the pair as "an odd couple." But, as he quickly pointed out, they have much more in common than would meet the untrained eye, and not only because their families share immigrant stories. The biographical parallels, Ocasio-Cortez told CNN, only resonate because Sanders is able to pull important threads --- like education, health care and immigrants' rights -- together in a compelling way.

"He's the only candidate that very solidly rests all of his policies on a principle of universality. So, he doesn't believe in means testing. He doesn't believe in asterisks. It's not about tuition free college if you're good enough -- it's about tuition free college in America," she said. "And so those principles of universality I think dovetail quite excellently with humane immigration policy."

Tailoring the message

Matt Barreto, a political scientist at UCLA and co-founder of Latino Decisions, the national polling and research firm, said that Sanders' policy and rhetoric around education, in particular, was resonating with Latino voters.

"The way he talks about education and college matches the sort of 'American dream' experience that a lot of first and second generation immigrant families think about," Barreto said, adding that, to many in the community, opening doors to higher education means "opportunity and access to social mobility."

Sanders' plan to cancel all student debt, however, Barreto warned, might have a less broad appeal, if only because many Latinos "are very nervous about accepting it" in the first place.

"The more common Latino experience is to possibly go to community college or the local Cal State L.A., or something like that, as opposed to, even if you get in, a USC or UCLA," he said. "So I think there's just that, again, that cultural understanding. It's a very white thing to go get a debt to pay for college."

Though concerns about access to higher education and health care -- Hispanics have the highest uninsured rate of all Americans, per recent Census information -- are routinely underrated by campaigns, immigration remains what a number of activists and organizers described to CNN as an "on-ramp" to credibility with Latino voters.

"What has happened under the Trump administration is that immigration has become shorthand for also standing up to hate speech and racism and everything else that we've been experiencing and seeing," Barreto said. "That was further exacerbated in all our polling after (the mass killing in) El Paso, where people started reporting that the number one issue they wanted to see addressed was racism against Latinos and immigrants."

The Democratic candidates have, in varying degrees, rushed to meet that standard. But there has been a sharp divergence both in messaging and on key policy questions, like whether to decriminalize the border and how to reform (or dismantle, in some cases) the deportation system, particularly with regard to the Immigration and Customs Enforcement agency.

Former Vice President Joe Biden has, so far, suggested the most moderate set of ideas. (His full immigration plan has not yet been released.) When confronted by protesters at a recent event, he defended the Obama administration's first-term record -- one that led activists to call Obama the "deporter-in-chief" -- and said he would not, like Sanders, put an immediate moratorium on deportations.

Sanders' pledge, which was one of the headlines to emerge from his immigration policy rollout, had an immediate influence on some progressive groups' view of the primary -- and potentially their endorsement processes, which have mostly come down to Sanders, Warren and Julián Castro, the former secretary of Housing and Urban Development.

Ana Maria Archila, the co-executive director of the Center for Popular Democracy, an umbrella group for dozens of community organizations, said Sanders' immigration platform "totally shifted the dynamics" of their internal discussions.

"When he says we're going to do a moratorium on deportations on Day One, that's huge," Archila said. "That is actually within the power of an executive, it is deliverable on Day One and it is so meaningful for people."

A 'nudge' to the polls

While progressive activists have been in an uproar over Biden's refusal to engage with their anger over Obama's policies, the former vice president's positions are mostly in line with the average Democratic voter. Sanders' challenge is to change that definition. To that end, he has impressed a number of Latino organizers with his efforts to consistently seek out, often with targeted digital content, underserved or traditionally neglected parts of the broader constituency.

The Sanders campaign offers "a case study in how strategic, continued, ongoing investment in a community can pay off," said Stephanie Valencia, co-founder of Equis Labs and Obama's deputy Latino vote director in 2008. "And I think one of the things we have come to learn is that there are certain elements within the Latino community who are primed to support Democrats and progressives, but aren't just going to turnout because it's an election. They need a nudge to the polls."

The prodding, or inspiration, can come from unexpected sources, Valencia and others said, all pointing specifically to the support Sanders has received from Cardi B, the pop star who joined him in July to film a chat about issues like climate change and raising the minimum wage.

Valencia, who described herself as "skeptical of celebrity endorsements," said that Cardi B's words, coupled with the backing of Ocasio-Cortez, who is 30, provided Sanders with "incredible validation with that community."

A progressive strategist with ties to Nevada, who asked to remain anonymous because of her organization's work in the primary, testified to Cardi B's influence with young voters who are mostly disengaged from the political process.

"I saw (my cousin) talking a lot more about Bernie post-the Cardi B endorsement. She's a makeup artist, she works in health care, she's a young mom," the strategist said. "When I asked her, 'Why do you support Bernie?' -- and she doesn't know what I do -- she's just like, 'Oh, because he wants to give everyone health care. He wants to provide free college, public college and, third, he's pro-immigrant."