Less than a week before the Nevada caucuses, Hillary Clinton’s political nightmare came to the Origin India restaurant near the Las Vegas Strip. More than 100 activists were packed between a curry buffet and a canvas sign for Bernie Sanders. They talked. They made caucus commitments. They cheered as a “multiethnic coalition” of speakers asked them to dump the longtime Democratic presidential front-runner.

“She had the same information as Bernie, and she voted for the war in Iraq,” said Vicenta Montoya, an immigration lawyer. “She supported a wall along the border. And while she was secretary of state, she did absolutely nothing to alleviate the hardship of people separated from their families.”

“The white Americans have already shown the momentum in Iowa and New Hampshire,” said Zaffar Iqbal, a doctor and a member of Muslims for Bernie. “Now is the turn for Nevada to stand up.”

Until quite recently, Clinton’s campaign saw Nevada as a chance for a face-saving victory after an anticipated defeat in New Hampshire. But that defeat turned out to be a trouncing. Now, the Sanders campaign is trying to prove that she can be beaten anywhere. ­Nevada, where the senator from Vermont is facing off against Clinton’s allies among organized labor leaders and a ­Latino-heavy electorate, has become the first test.

Democratic presidential candidate Hillary Clinton takes a photo with a supporter's cell phone Sunday at a get-out-the-vote evnet at a Las Vegas community center. (Ethan Miller/Getty Images)

Clinton’s hopes rested on her overwhelming advantage among voters of color — part of a “firewall” her aides have claimed in many states that follow overwhelmingly white Iowa and New Hampshire on the electoral calendar. Sanders, however, is betting that his appeal among young and working-class voters, revealed so dramatically in New Hampshire, is strong enough to transcend race.

Nevada is a chance to disprove “this firewall fantasy that the Clinton campaign has put out there,” said Jeff Weaver, Sanders’s campaign manager. “If we do well, it destroys that myth.”

Sanders’s aides say there is strong evidence in their internal polling that young and working-class Latinos are coming his way. Even the Clinton campaign is now playing down expectations. In a conference call with reporters last month, campaign manager Robby Mook said Clinton held a 25-point lead in the state. But in the wake of the New Hampshire defeat, Clinton spokesman Brian Fallon pointedly called Nevada “a state that is 80 percent white voters,” universally seen as a way to undercut the story that Sanders is making gains outside of progressive white voters. (In 2008, fewer than 70 percent of ­caucus-goers were white.)

And both campaigns competed intensely in the state over the weekend — with more appearances to come before the caucuses in five days. On Saturday the San­ders campaign asked in an email for “volunteers across the country to help us call Spanish-speaking voters in Nevada and find out who is for Bernie and who is still undecided.” Clinton’s campaign deployed squads of Spanish-speaking union members.

Twelve Sanders campaign offices have mushroomed across the state. He is outspending Clinton in TV ads by roughly 2 to 1, according to the Las Vegas Review-Journal. Those ads, which began in November, now feature the Latina politician Lucy Flores, a former state legislator, explaining why she thinks only Sanders can fix the country. More than a hundred paid staffers have hit the ground, aided by Latino pro-Sanders groups from as far away as Los Angeles. On Sunday, San­ders even wound up in the same black Las Vegas church as Clinton, sitting at the opposite end of the first pew.

“The people of Nevada were some of the hardest hit by the Wall Street meltdown,” Weaver said. “People lost their homes, they lost their jobs.”

Democratic presidential candidate Sen. Bernie Sanders speaks at a Las Vegas high school Sunday. (Ethan Miller/Getty Images)

Clinton’s performance in Nevada’s 2008 caucuses taught her campaign two crucial lessons heading into this year’s race. Her victory in the popular vote revealed an advantage against ­Barack Obama among Latinos and Las Vegas union workers — an advantage her supporters anticipated would grow even stronger against Sanders. And her loss in the delegate count, despite the popular-vote win, revealed an organizational weakness and strategic shortcoming that her aides vowed to correct this time around.

Mook ran that 2008 Nevada campaign. As the caucuses neared, the culinary workers, an important constituency, were on the fence.

“The Culinary Union endorsed Obama at the last minute,” Rep. Dina Titus (D-Nev.), a Clinton endorser, recalled during a visit to one of Clinton’s seven campaign offices over the weekend. “Then, the members voted for Hillary. It was really something to see.”

The reverse may be happening this year. Despite Clinton’s overwhelming support among union leaders, the Sanders campaign is making a concerted bid among the rank and file. And if his disadvantage among minority voters is fading, the Sanders campaign sees that as part of the pattern; as he becomes better known, supporters say, voters from every demographic warm to him.

The contrast was stark at the two candidates’ first post-New Hampshire rallies in Las Vegas. For Clinton, it was at a union hall in the suburbs, plastered with the banners of her labor allies — the American Federation of State, County and Municipal Employees, the ironworkers union, the bricklayers, the American Federation of Teachers, and Service Employees International Union Local 1107. Less than a thousand turned out, many of them at the behest of their unions. And among the die-hards were people considering voting for Sanders.

“Hillary messed up on a couple big things,” said Miguel Landeros, a 19-year-old apprentice brick­layer who had come to the rally because the union was turning out members.

“People can say anything, but you’ve got to find out whether they’ve acted,” added Jose Ceniceros, also 19 and a member of the union.

Those young Latinos were outnumbered by activists who could count the ways Bill Clinton’s presidency had helped them — and by union members who were cold to Sanders’s promise of revolution. “The presidency is not some Jet Ski that you ride over the waves of partisanship,” Linda Overby, 58, said.

Clinton’s pitch was tailored precisely for skeptics like Overby. The former secretary of state recalled the 2008 economic crisis and suggested that the Obama administration deserved more credit than it had received for financial reform and the Affordable Care Act.

“This state was especially hard hit,” Clinton said. “Too many people lost their jobs. Too many people lost their homes. I remember going door to door in 2008, walking streets and neighborhoods, into people’s homes, people who had done everything right but couldn’t keep going because one family member had lost a job.”

Clinton also has reached out relentlessly to Latino voters, starting last year with an emotional roundtable with “Dreamers” — undocumented Latinos brought to this country as children — to whom both Clinton and Sanders favor granting legal status.

The Sanders campaign, with a later start on the ground in Nevada, simply contrasts that with the consistency of his pitch for income equality. Over the weekend, the campaign dispatched surrogates who included Rep. Raúl M. Grijalva (D-Ariz.) and Chicago mayoral candidate Jesús “Chuy” Garcia to rev up young voters and talk to union members. More than 30 shop stewards from the culinary union had a meeting with Grijalva, who then sped over to a town hall meeting where dozens of Sanders volunteers got an education on immigration policy.

“People committed a year ago, seven months ago, and committed to Hillary regardless of what was going to happen,” Grijalva said. “But members are not locked in.”

The town hall was light on criticism of Clinton and heavy on policy. But the volunteers also learned what to say if anyone repeated a critique Clinton had made: that Sanders’s vote against the 2007 immigration bill meant he was not a true ally.

“I would have voted against it, too,” Grijalva said. “She voted for the fence, and Bernie didn’t. So what does that say?”

Sanders’s rally at a high school gym on Sunday was at least twice as large as Clinton’s, and the senator picked up a bullhorn to thank an overflow crowd. It skewed young, and it appeared to make converts out of people who had only just heard of Sanders.

Inside the gym, a boisterous crowd repeatedly interrupted Sanders with cheers and chants of “Bernie! Bernie! Bernie!” as he ripped through his 45-minute stump speech, decrying the influence of the “billionaire class” and recounting his progress in a race against “the anointed candidate of the establishment.”

Ferdinand Deguia, 28, a cook who said he was astonished to get a W-2 form that showed he made only $23,000 last year, said ­Sanders appealed to him on several counts. Among them: his pledges to raise the minimum wage and offer free tuition at public universities and colleges. And Deguia liked what Sanders had to say about criminal justice reforms.

“I have friends and family who’ve got into the system, some for drug offenses, some more serious,” Deguia said. “I’ve seen it myself, the revolving door, and someone’s got to do something about it.”

Anne Gearan in Washington contributed to this report.