Hillary Clinton swept the Las Vegas Strip, winning all six casino caucus sites. | AP Photo How Clinton staved off disaster in Nevada Putting its money into organizing, not ads, her campaign held off Sanders' late surge.

LAS VEGAS — Nevada wasn't the Western firewall Hillary Clinton's campaign once boasted about, but it was strong enough to hold back a late surge by Bernie Sanders — and give Clinton's embattled campaign such a morale boost her Brooklyn headquarters erupted in cheers of relief when her five-point win was announced late Saturday.

Earlier in the campaign, many of them would have scoffed at the idea that a five-point victory over Democratic socialist Bernie Sanders would have been something to cheer about. But after Clinton's drubbing in New Hampshire, more than a few of her campaign operatives had begun to fear that Nevada, too, might tilt into the Sanders column.


The sense of relief extended to the candidate herself.

“To all of my supporters out there,” Clinton told the enthusiastic crowd at her victory rally in an upstairs ballroom at Caesar’s Palace, where Clinton had been staying for most of the week, “some may have doubted us but we never doubted each other!”

As modest as her victory margin in Nevada was, it was her first clean win of the campaign. After an Iowa victory by less than a percentage point and the 22-point loss in New Hampshire, the single-digit victory marked a welcome shift in momentum. The campaign was eager to make hay. Communications director Jennifer Palmieri called it the best day of the campaign to date.

More crucial for campaign staffers looking ahead to the Feb. 27 South Carolina primary and the March states that follow was Clinton's dominant performance among black voters here.

Clinton swept the Las Vegas Strip, winning all six casino caucus sites, which tend turn out a highly diverse population of culinary workers. Bill and Hillary Clinton had spent the week feverishly working the back rooms and cafeterias of casinos like Harrah's and Caesar's, furiously hunting for votes.

And she won a decisive 76 percent of African-American voters across the state, according to CNN exit polls. Clinton also won all the delegates in districts that were at least two-thirds African American, according to a campaign aide.

But despite the huge sighs of relief in the Clinton camp, her erosion of support in a state where she was leading by more than 25 points in polls less than a month ago still raised some concerns for the campaign as it forges ahead.

The premise of Clinton’s early state strategy was that Sanders could not play in diverse states more reflective of the country than the largely white populations of Iowa and New Hampshire. But his strong showing here proved that his message about economic inequality could appeal to a broader coalition of voters. After her defeat in New Hampshire, Clinton admitted she still has work to do to attract the support of young voters. And even with the support of millennial Latino actress America Ferrera working hard here and knocking on doors, she did little to bridge the gap with Sanders among young people. He won 83 percent of millennial voters, according to CNN exit polls.

Sanders’ campaign was quick to claim he still had the wind at its back, even in a loss. “I want to be completely clear with you about what this result means,” Sanders wrote in an email to supporters shortly after the race was called. “Nevada was supposed to be a state ‘tailor made’ for the Clinton campaign, and a place she once led by almost 40 points. But today, we sent a message that will stun the political and financial establishment of this country: our campaign can win anywhere.”

Hillary Clinton on Nevada win some people 'doubted' us An excerpt Hillary Clinton's remarks in Nevada.

The ethnic breakdown, however, shows Sanders campaign suffers from some possibly insurmountable barriers going forward. His poor showing among black voters means he is unlikely to close Clinton’s 18-point lead in South Carolina, where the Democratic population is 60 percent African-American. He even seemed to forget about the next primary when he told supporters, "now it's on to Super Tuesday!"

Clinton’s win was also testament to the stay-the-course strategy of campaign manager Robby Mook, who began building his staff on the ground here back in April. Even as Sanders began outspending Clinton on television by a 2-1 margin, Mook stuck to his philosophy that what matters more than ads was how long organizing offices have been on the ground with their doors open to the community.

Mook, who ran Clinton's Nevada operation in 2008 when she won the popular vote but lost by one delegate to Barack Obama, trusted his strategy. The campaign had 1,000 committed precinct captains across the state. And it vowed to stay the course and not become reactive while Sanders swiftly opened more field offices, hired staffers, and went big on television.

Loyal staffers were thrilled with the win for the campaign manager, eager to buoy the operative who has been forging ahead and trying to drown out discouraging news reports about his possible demotion. “Mook! Mook! Mook!” they cheered in Brooklyn headquarters as Clinton took the stage to thank her supporters. There, she appeared energized, with Bill Clinton looking on with pride.

"I want to thank each and every one of you," she said. "Hotel and casino workers who never wavered. Students with too much debt and small business owners who never go off the clock. Tens of thousands of men and women with bills to pay and dreams that won't die, this is your campaign. it is a campaign to break down every barrier that holds you back."