If you want to know why Saturday's Nevada caucus has suddenly, in its final weeks, turned from a presumed landslide for Hillary Clinton into a total toss-up, ask Emily Sandoval and Maggie Salas-Crespo.

Or rather, don't. It's not that they're uninformed; both Sandoval and Salas-Crespo are politically engaged (they work for a small political consulting firm) and are closely following the Democratic primary. But as of last week, at least, they were still in the uncomfortable position of not having made up their minds.

"That ... is a very good question," Sandoval, said, squirming. Salas-Crespo, nudged her: "You go first," and Sandoval sighed. "I'm a little broken between Bernie and Hillary," she said.

She struggled to explain why. But her friend Eric did it for her: It's a struggle of "head versus heart."

Hillary Clinton wasn't supposed to have to fight this hard for their votes. Their generational peers in Iowa and New Hampshire voted overwhelmingly from Bernie Sanders, but they weren't expected to follow suit. Instead, the Clinton campaign expected nonwhite voters (Latinos in Nevada and black voters in South Carolina) to provide Hillary with a couple of easy wins after getting shellacked by Sanders in blindingly white New Hampshire.

That's not happening. The race in Nevada is neck and neck heading into Saturday's caucuses — and available polling suggests nonwhite voters are split between Sanders and Clinton.

Young Latinos — who make up nearly half of Nevada's Latino voters — don't have the rosy memories of the 1990s that helped drive Clinton to victory with Latinos across the country (including in Nevada) in 2008. Instead, the president on their mind is Obama. They're still wrestling with his failure to keep his campaign promise to pass immigration reform, and the record deportations of his first term. But while they're not inclined to fall in line behind a candidate that represents the political establishment that disappointed them, many are equally wary of falling in love with another candidate who promises to transform the political order.

The weight of choosing a candidate is heavy, because in this, as in all politics, many young Latinos carry the responsibility of choosing a candidate on behalf of their relatives and community members who can't vote. In the days leading up to the caucuses, they were still struggling to figure out who could be entrusted to protect them and the ones they love.

A frustration deeper than Trump

Several Latino and immigration advocacy groups have been pushing "the Trump effect": the idea that Donald Trump has attracted so much attention for saying offensive things about immigrants that it will mobilize record numbers of Latinos to the polls to vote against him.

That might be true. "With Mr. T in the mix, it has sparked a lot more interest," says Salas-Crespo. "I have family members who've been legal permanent residents [green card holders] for 30 years" who had never thought of becoming citizens and voting. Now they're thinking about it.

Salas-Crespo herself is part of a younger generation: Latinos under 30 whom University of Nevada Las Vegas professor David Damore describes as "more politically engaged, as compared to prior generations." They make up nearly half of Nevada's Latino voters, and many of them didn't need the Trumpian wake-up call.

Furthermore, Saturday's caucuses throw into relief that it's not enough to vote against a candidate. Latinos can't vote against Trump on Saturday, and no one I spoke with in Nevada was inclined to caucus with the Republicans to block him. Instead, Latino voters are looking assiduously for someone to vote for.

Some of them have found it. Both the Sanders and Clinton campaigns have made significant efforts to reach out to Latino voters of all ages. Sanders has a core of young Latino volunteers who his campaign hopes will rally their community to a caucus victory. And there's definitely some enthusiasm for Clinton as well: Michael Gonzalez, a voter registration organizer, says there are plenty of people who complete their registration forms, hand them back to him, and shout "Hillary!" as they walk away from his clipboard.

But most of the young Latinos I talked to in Nevada weren't yet able to get fully behind either candidate.

"My biggest fear," says Jocelyn Sida of the civic engagement group Mi Familia Vota, "is that the mentality of Latinos is going to be all about broken promises, don't trust any candidate or campaign, and just vote for the sake of it. I want them to vote with purpose. I want them to vote to support candidates and issues they're passionate on."

But Sida's reference to "broken promises" is right on. For many — especially for young Latinos, many of whom came of political age during the Obama administration — the outgoing president is associated with the promise he made, then broke, on immigration reform, as well as the deportations that took place in its stead.

"When President Obama went into office, he was talking about immigration reforms," says local activist and Sanders supporter Liz Hernandez. But still, in 2016, "I live in fear for my parents, knowing that at any time they could be deported."

"I'm not saying Obama hasn't done anything for us," Hernandez continues — she herself got protection from deportation and work eligibility after Obama's 2012 executive actions. "But that does not mean that I cannot be critical of the deportations that are happening now."

Hernandez can't vote. But both citizens and noncitizens I spoke to in Nevada agreed: Members of the community who can vote bear the responsibility of voting on behalf of those who cannot.

Young Latinos take this responsibility especially seriously — in a way that makes them less partisan than their older peers. In 2014, asked why they voted by the polling firm Latino Decisions, Latinos as a whole were only slightly more likely to say they were voting to "represent the community" (37 percent) as to support the Democratic Party (34 percent). But among Latinos under 35, only 28 percent said they'd come out to support Democrats; 50 percent, nearly twice as many, were voting on the community's behalf.

Who can Latinos trust? And how do they know?

So which of the two Democrats running for president — if either — deserves to be entrusted to protect the Latino community?

This is the question lurking behind the pre–Nevada caucus uncertainty. And plenty of Latinos simply aren't inclined to trust anyone. "People right now, they doubt a lot of the candidates because of the last eight years," says Hernandez.

It's not that people are totally disengaged. They're proactive in their skepticism — using it to test the candidates. "People are more focused on actual actions, on how they voted, being more skeptical."

In some cases, that skepticism is extending to the Democratic Party as a whole. "A lot of Latino voters are inclined to vote Republican this year, more than 2008," Diaz says — at least, to vote for Republicans who are "more non-conservative." On the other end of the spectrum, Aldo Chavira, a UNLV student who wears "Bernie!" pins on his shirt and backpack, says he might not bother to vote for the Democratic nominee if it isn't Sanders: "I feel like there isn’t much difference between the parties now. If he didn’t win the nomination, that’d be one of the last times that you could vote for somebody honest."

Liz Hernandez doesn't go so far as to say that both parties are the same, but she also believes Sanders's anti-establishment cred makes him the anti-political politician Latinos are seeking, because he offers "hope."

Diaz sees it differently: that falling in love with Sanders is making the same mistake all over again. "When I hear Bernie Sanders talk about certain immigration points, it reminds me of Obama. Like, I've heard that before. I want to hear something different."

Of course, it's hard to judge candidates based on their actions in the midst of a presidential candidacy, which is all about words. But some Latinos are making their decisions based on how well they feel the candidates are reaching out to their community — how much, in other words, their vote and input is being valued.

"Because of outreach, I'm leaning toward Clinton," says Diaz. "I feel like she's been trying to keep people more involved." On the other hand, another young Latina who asked not to be named said that she'd only been contacted on behalf of the Sanders campaign — by a woman who spoke in passionate and fluent Spanish. "It was amazing!"

Alternatively, they can judge by how well the candidates respond when they're called out for their inevitable shortcomings. "We always have to be vigilant," says Astrid Silva of the group DREAM Vegas. Silva isn't eligible to vote, but she's endorsed Hillary Clinton. "We gave her a lot of the criticisms we had, and of all the candidates she handled it the best."

Latino voters don't have the luxury of idealism

Most young Latinos don't have the luxury of sitting down and grilling the candidates. But Silva's attitude of engaged skepticism is pretty common among her peers.

"I work a lot with the youth," says Emily Sandoval. Searching for the right euphemism, she adds, "You see more of an ... innocent essence in what they would like to see in this country."

In a primary election that's been defined by a generation gap as much as anything else, you might associate that sort of pragmatism with the over-45 voters drawn to Hillary Clinton.

Sandoval — who was undecided as of last week — is in her mid-20s. She has only voted for one president before. But paying close, personal attention to the Obama administration's failures and limitations over the past eight years has made her especially wary of candidates who appeal to her "heart."

Freddy Garcia is even younger — he really is one of those first-time voters. At a mock caucus on Saturday he was also undecided, saying he had to do some research on the candidates' immigration positions before making up his mind.

When his fellow mock caucus attendee — also a Latino and first-time voter — declared his support for Sanders, he started evangelizing not so subtly to Garcia. The actual mock caucus hadn't started yet — and it was using fake candidates anyway — but Garcia was getting a taste of the real caucus.

"It's time for change," the Sanders supporter said. "People keep saying he's not going to do that change, but they're the naysayers. If you believe the change, it will happen."

Garcia sighed. "Literally every candidate in history has promised change," he said. He sat sideways in his chair, turning his back to the evangelism.