Also, some pollsters question the depth of Sanders’ support among Latinos in Nevada and elsewhere.

Stephanie Valencia of the Latino-focused Equis Labs, said it remains to be seen whether it’s Sanders "the candidate" or the broader "movement" he’s leading that attracts Latinos. Her polling reflects Sanders' strength among the demographic, especially young Latinas.

“Do people who are Latino Bernie supporters feel so strongly about him that they're going to show up and caucus for him?” Valencia said. “Because it's one thing to show up and vote for somebody, it's another thing to go and caucus for somebody.”

But Sanders’ campaign is acutely aware that his polling strength among young Latinos won't necessarily translate in a caucus state like Nevada, given the time and effort required of voters. Young voters, regardless of race, are historically the least likely group to turn out.

That’s why his campaign said starting early was crucial. In 2016, his advisers didn’t realize Sanders' potential with Latinos until late, said Rocha. Everything was “moving so fast, we never had time to go build our relationships in that community,” he said.

“We wanted to start the campaign where we left off, so we started in the Latino neighborhoods,” Rocha said. The first of 11 field offices it opened in Nevada was in the largely Latino East Las Vegas. And the first TV ads Sanders purchased in the state were in Spanish. “We’re blowing people out organizing-wise,” Rocha said.

Ironically, part of the campaign's effectiveness among Latinos stems from the fact that it did not create a separate arm for courting Latinos, said Analilia Mejia, Sanders' national political director. Instead, outreach to Latinos was integrated into every part of the organization. No matter the topic of a press release, Mejia said, a Latino staffer has looked at it before it goes out.

One of Sanders’ first messages to Latinos in Nevada came in an August mailer that told the senator’s family immigration story. That was followed by issue-specific mailers, including one in November prominently featuring progressive star Rep. Alexandria Ocasio-Cortez (D-N.Y.). Ocasio-Cortez held a town hall for Sanders in December entirely in Spanish, a rarity that drew widespread notice in the Latino community. Notably, Ocasio-Cortez is not scheduled to campaign for Sanders in Nevada in the final days before the caucuses.

Sanders' final Spanish-language TV ad to Latinos this week was narrated, written and produced by Dreamers on his staff, according to the campaign.