In this edition: How to win the Nevada caucuses, how Elizabeth Warren is trying to come back, and how Mike Bloomberg qualified for the Las Vegas debate.

If you like maps, you have come to the right place, and this is The Trailer.

LAS VEGAS — When they campaigned in Iowa, Democratic candidates apologized to the state's voters for ignoring them in 2016. When they campaigned in New Hampshire, they thanked voters for a string of suburban victories, while bemoaning how overwhelmingly white states still controlled the primary process.

Democrats have talked differently about Nevada, a state where they see an ideal American future — diversity, strong labor unions and an electorate racewalking away from the Republican Party. Former vice president Joe Biden can't say enough about the power of Nevada's nonwhite voters; former South Bend, Ind., mayor Pete Buttigieg talks happily about how by 2050, America will look like Nevada.

“This is the United States of America you see in this room tonight,” Gov. Steve Sisolak, the first Democrat to lead the state in 20 years, told reporters before Saturday's fundraising dinner for Clark County Democrats. “Democrats have to appeal across all demographics, across all economic divisions, and Nevada's the place to do that.”

Nevada’s elections and caucuses are dominated by Clark County, from Las Vegas to its fast-growing suburbs. In 2016, nearly three-quarters of all votes came from the county, and they broke solidly for Hillary Clinton, securing her victory even as she lost Reno’s Washoe County to Sen. Bernie Sanders. This newsletter broke down the Democratic electorates of Iowa and New Hampshire by looking at key counties, but that's not necessarily a helpful way of viewing Nevada, where most of the vote will come from two urban centers.

A better way to look at Nevada is to copy what Democrats themselves will do: Watch the vote in each congressional district. Thirteen of the state's 36 delegates will be split up according to the statewide vote, while the rest will be parceled out across the districts. In 2008, that helped Barack Obama edge Hillary Clinton in the delegate count, thanks to his dominance outside Clark County. In 2016, it padded Clinton's lead, as she carried three of four districts. 

Only two early Democratic contests have been held in Nevada, and the state has never seen a race with as many candidates as this one. Six Democrats are actively competing here: Biden, Buttigieg, Sanders, Sen. Elizabeth Warren (D-Mass.), Sen. Amy Klobuchar (D-Minn.) and investor Tom Steyer. Here's where they're hunting for votes.

The 1st Congressional District is the smallest battleground of the primary so far, covering just a few heavily populated square miles from old Las Vegas down to McCarran International Airport. It’s the least-white district in the state, too; 45 percent of its residents are Latino, 13 percent are African American and 8 percent are Asian American. It's the youngest district in the state, as the retirees who keep relocating to Nevada are concentrated in the outlying suburbs. And it's the least-wealthy part of the state, with working-class immigrants and younger middle-class voters living on either side of the Strip.

On caucus day, the most closely watched battles will be taking place in the casinos here, where service workers, many of them members of Culinary Workers Union Local 226, will use break time to vote. The union's non-endorsement in this race was most harmful to Biden, who has nonetheless continued to make unannounced stops to talk to workers. But the real trends in the Latino vote will be visible in East Las Vegas, where the Sanders campaign has out-organized the field. (He has 250 staffers in the state, and other campaigns already talk as if they can do no better than second place.) Sanders and Buttigieg have three campaign offices in the district, Warren has two, Biden and Klobuchar have one and Tom Steyer has none.

2016 result: Clinton 53%, Sanders 47%

The 2nd Congressional District is the whitest in Nevada, and the most reliably Republican, stretching 400 miles from Lake Tahoe to the Utah border. Most of the Democratic votes will come from Reno, where there is a true dogfight for first place and where the most reliable caucus-goers — middle-class liberals, many of whom moved to the state from California — are cool on Sanders but divided among Warren, Buttigieg, Biden and Klobuchar.

Just one-fifth of caucus-goers here, or less, are likely to be nonwhite; 23 percent of all residents are Latino, 4 percent are Asian American, 2 percent are Native American and 2 percent are black, while white voters are more likely to turn out. Diversity is harder to come by in tiny Elko and in the smaller towns along Interstate 80 than in Reno. Buttigieg is the only candidate to visit Elko in the race's last week, and Sanders won the city and its namesake county by 12 points four years ago. But there simply aren't many votes outside of the population belt that connects Reno to Carson City. Sanders and Buttigieg have four offices across the district, Warren has three, Biden has two and Steyer has one. 

2016 result: Sanders 54%, Clinton 46%

The 3rd Congressional District is the fastest-growing part of the state and the only one where a majority of eligible voters have completed college degrees. Nearly half of all voters live in Henderson, a prosperous Las Vegas suburb; the rest live in smaller suburbs or in the small towns scattered throughout greater Clark County. Just 18 percent of residents are Latino and 8 percent are black, but 14 percent are Asian American, the largest concentration of those voters in the state.

The campaign here looks like the campaign for suburbs across the country, with some skepticism of Sanders but indecision among moderate voters. Buttigieg's first legislative endorser in the state, Assemblywoman Sandra Jauregui, represents part of these suburbs, but he has not scheduled any final-stretch events yet in Henderson. Nor has Sanders, though he has two local offices and other candidates have just one. Warren held the largest post-New Hampshire event in the district, pulling 400 voters to a Monday afternoon town hall, more than had come to Biden or Klobuchar events in the city. If the senator from Massachusetts can pull off a recovery in Nevada, it will start here; if suburban voters are moving to Buttigieg and Klobuchar as they did in New Hampshire, it will be most visible in Henderson.

2016 result: Clinton 53%, Sanders 47%

The 4th Congressional District is deceptively large, running from northern Las Vegas through the rocky rural counties more than 100 miles away. But 90 percent of the vote comes from Clark County and includes North Las Vegas, poorer and more diverse than its more famous city to the south. One in five of the city's residents was born outside the United States, and one in five is black.

Other, smaller population hubs, such as Pahrump and Ely, are smaller and less racially diverse and have few Democratic voters; overall, 32 percent of the district's residents are Latino, 14 percent are African American and 6 percent are Asian American. If Joe Biden is doing well Saturday, he's probably running strongest here and was helped over the early-voting weekend when Rep. Steven Horsford, the first black member of Congress from Nevada, officially endorsed him. The vote from Summerlin, a retirement community with more than 100,000 residents, will also reveal whether Biden's strength with older Democrats who reliably vote holds up in Nevada. 

Warren and Buttigieg have two offices in the district, the most of any candidate, and one of Buttigieg's is in Republican-heavy Pahrump, an example of his outreach to frustrated conservatives. But a particularly strong Biden performance would be crucial to a second-place statewide finish, the kind his campaign is predicting.

2016 result: Clinton 59%, Sanders 41%

Reading list

“Campaigns warn of chaos ahead of the Nevada caucuses,” by Holly Bailey

Iowa, but hotter? Democrats are trying to avoid that.

“ ‘This race is really wide open’: Uncertainty hangs over final sprint to Nevada,” by Alex Roarty

The muddle for Nevada.

“Klobuchar scrambles to turn her magic moment into something more,” by Annie Linskey, Jenna Johnson and Holly Bailey

Hiring a “Nevada operations director” for the first time, and other ways Klobuchar is learning on the run.

“With Sanders at the top of the ticket, will Democrats keep the House seats they won in moderate districts?” by Jennifer Haberkorn

Fear of a democratic socialist on the ballot.

“The Democratic nomination contest doesn’t look like any from the past,” by Dan Balz

Why it's so hard to see what happens next.

“I watched 185 Mike Bloomberg ads,” by Justin Peters

Ranking the Bloomberg charm offensive.

On the trail

HENDERSON, Nev. — Elizabeth Warren has a cold. 

It became a problem Saturday, shredding her voice right before she took the stage at a party dinner. It chased her throughout the weekend, rendering her nearly inaudible at what could have been a triumphant town hall in Reno — more than 1,000 voters showing up for a candidate who had vanished from coverage of the race.

“You can tell I’m a little husky, so I’m saving my voice,” Warren said the next day in this city south of Las Vegas. “We’ll get to talk about plans and whatever else people want to talk about!”

Warren, seen not so long ago a top contender, is now playing for second place after a long run of setbacks. Some were bad luck: The cold, which the candidate jokingly blames on her “selfie lines.” The vote-count debacle in Iowa, which robbed Warren of a prime-time speech and momentum heading into New Hampshire. Some came from genuine miscalculation, like the New Hampshire debate at which she stayed quiet and careful, while Amy Klobuchar took risks.

One week later, Warren's campaign in Nevada is outnumbered (50 staffers, less than half of that of her top rivals) and outspent ($1.2 million, dwarfed by Tom Steyer, Joe Biden and Pete Buttigieg). And the candidate's supporters are growing restless, taking note when their news shows fail to mention her, grumbling at the attention Mike Bloomberg is getting.

“Bloomberg is sucking the air out of the room right now,” said Cathy Rosenfield, 61, as she waited in Warren's Henderson selfie line. “I think you guys in the media are doing what you did with Trump four years ago.”

Warren's campaign has avoided the sort of leaks, backbiting and recrimination that bedeviled other campaigns during their slumps. Its venting is very public, with the candidate talking more about whether female candidates get underrated and the campaign running ads about the media erasure.

“The night of the Iowa caucuses, CNN didn't air Elizabeth's full speech, but they aired the speeches of other candidates she beat,” reads one Warren ad now running on Facebook. “We can't count on the media to cover our campaign fairly, so we're taking our case directly to voters.”

The media has not abandoned Warren, but since Iowa, she has struggled to make news. In Nevada, at least one news outlet reassigned a reporter who had been covering Warren to cover Klobuchar instead; the senator from Minnesota held no public events Sunday or Monday, phoning in to a San Francisco fundraiser and then attending one in Los Angeles. Warren, who has rarely appeared on Sunday talk shows or cable news, has given more on-the-record time to reporters, talking for 30 minutes to her traveling media corps and doing an MSNBC interview after her last Monday night stop, at a Latino grocery store in Las Vegas.

In those interviews, a candidate who has been relentlessly on-message, who diverted questions about polling or Trump tweets to her story of government corruption, has begun to swim in the news cycle. In that MSNBC interview, she responded for the first time to the Culinary Union's claims that supporters of Bernie Sanders had harassed their leaders over criticism of Medicare-for-all.

“The whole notion of publishing their personal addresses, their phone numbers, and then making very aggressive threats against their own safety and the safety of their families — that is not how we build an inclusive Democratic Party,” Warren told reporter Ali Vitali. “We do not build on a foundation of hate.”

Warren's month-old positioning as the “unity candidate,” the Democrat who could save the party's centrists from Sanders while largely satisfying left-wing voters, did not win her votes in the first two states. In Nevada, where ranked-choice voting and caucus rules allow second-choice candidates to thrive, the strategy could be more effective. It relies on Warren showing up, looking credible and capitalizing on the idea that a qualified female candidate is being nudged out of the race.

“Look, I'm a black woman, right?” said Joy Boggs, an administrator at the University of Nevada at Las Vegas who came to see Warren in Henderson. “I'm a nerdy black woman, and I've been the most qualified candidate in a room where the powers that be are white guys.”

On Monday, as Warren's voice slowly recovered from the cold, she had Las Vegas largely to herself. Sanders, comfortably ahead in this state, was campaigning in a few western states that vote in March. Buttigieg and Biden were raising money and stumping in Reno. 

That gave Warren time for a busy yet unhurried day of campaigning, where she spoke to voters for a combined two hours, sometimes in smaller groups. She headed from Henderson to Las Vegas for a town hall with SEIU members, where the questions were friendly and where she promised a union that had yet to endorse in the presidential race that no one would do more for them.

“My gratitude runs all the way to my toes,” Warren said. “Whenever SEIU is out on a picket line, whenever they're in the middle of negotiations, all they have to do is pick up the phone. I got this Senate seat because of the fight for working people.”

An hour later, she was at the supermarket, introduced by former HUD secretary Julián Castro and a troupe of Mexican folk dancers. She took harder questions there, on everything from the departure of nonwhite staffers from her Nevada campaign (“I believe these women without reservation”) to whether she would appoint at least four Latinos to her Cabinet (“Are you going to limit me to four?”) to whether there were any Latinos in real positions of power in her campaign.

“Are you kidding? I’ve got Julián!” Warren said, as nearby shoppers paused at a tamale stand to listen.

When the event was over, Warren posed for more photographs, the selfie line wrapping up in about 15 minutes. Jeri Burton, 61, had worn her Equal Rights Amendment button to the event, promoting the work she did with the National Organization for Women to get the deadline for ratification extended. Like many of the people who saw Warren speak, she figured that a little more media coverage would fix whatever problems the senator had brought to Nevada.

“We've seen Amy get some attention, but Senator Warren seems to be left out of it,” Burton said. “I've seen people on Twitter saying, hey, what about Warren? But she's third in the delegate count. I don't want to see people discount her." 

Ad watch

Amy Klobuchar, “Bienestar.” The Minnesotan's first Spanish-language TV ad, ever, makes like her English-language ads: It portrays her as the “best candidate” to win the election. “We Nevada Democrats must elect a candidate who can actually defeat Donald Trump,” a narrator says over still images of the senator. “And that person is Amy Klobuchar.” Unlike Pete Buttigieg, who has also been introducing himself to many Nevadans for the first time, Klobuchar does not speak Spanish in the ad.

Bernie Sanders, “Nevada First.” One of few ads that focuses specifically on Nevada issues, this spot pitches Sanders as the candidate with an immigrant-friendly, economy-friendly green jobs plan perfect for a state that's often on edge about climate change and the potable water supply. “Only Bernie Sanders has a plan bold enough to avert the climate crisis and put Nevada first,” a narrator says.

Mike Bloomberg, “Greenwood.” Aimed at black voters, this spot quotes from the speech Bloomberg made to black voters in Tulsa, promising an agenda of racial restitution that could surprise activists who fought him over stop-and-frisk and gentrification. “Americans systematically stole black lives, black freedom and black labor,” he says.

Poll watch

2020 Democratic primary by region (NPR/PBS NewsHour/Marist, 1,416 adults)

Big Cities

Bernie Sanders: 33% 
Mike Bloomberg: 17%
Joe Biden: 17% 
Elizabeth Warren: 11% 
Pete Buttigieg: 6% 
Amy Klobuchar: 5% 
Tom Steyer: 3% 
Tulsi Gabbard: 2%

Suburbs

Bernie Sanders: 26% 
Mike Bloomberg: 18%
Elizabeth Warren: 15% 
Pete Buttigieg: 13% 
Amy Klobuchar: 11% 
Joe Biden: 9% 
Tom Steyer: 1% 

The real-world impact of this poll was immense: Bloomberg hit 19 percent, qualifying him for tomorrow night's debate. (More about that below.) But the crosstabs are more revealing than the generic national numbers. As we saw in Iowa, then saw again in New Hampshire, Sanders has taken command of the Democratic race with a different coalition from the one that let him go the distance four years ago. He is dominant in cities, as evidenced by the return of his 10,000-plus-person rallies this week. But he has lost ground in suburbs and rural areas, benefiting from how the voters in those parts of the country are flummoxed by their choices.

Virginia Democratic primary (Monmouth, 400 Virginia voters)

Mike Bloomberg: 22%
Bernie Sanders: 22% 
Joe Biden: 18% 
Pete Buttigieg: 11% 
Amy Klobuchar: 9% 
Elizabeth Warren: 5% 
Tulsi Gabbard: 1%

Virginia is one of six Super Tuesday states with no party registration, where voters can show up and pull any ballot they like, regardless of their vote history. (The other five: Alabama, Minnesota, Tennessee, Texas and Vermont.) In 2016, that rule was often helpful to Bernie Sanders, who remains an independent even as he seeks the Democratic nomination for the second time. This year, marginally, the rule is a bit better for Bloomberg; he nudges past Sanders with non-Democrats but falls behind him among people who identify as members of the party.

Debate season

Mike Bloomberg has qualified for tomorrow night's Democratic debate in Las Vegas, after hundreds of millions of dollars' worth of advertising boosted him from single digits to second place in national polls.

The crucial poll came early Tuesday, when NPR and Marist released numbers that put Bloomberg at 19 percent support, 12 points behind the resurgent Bernie Sanders. That gave Bloomberg the fourth of the four polls necessary to make the debate stage, in a state where he is not even competing. The billionaires microphone that belonged to Tom Steyer in recent debates will be passed to Mike Bloomberg; the deadline for qualifying polls is tonight, and Steyer still needs three of them to get onstage.

Every other candidate onstage has signaled some happiness about the outcome. Amy Klobuchar had been urging the party for weeks to pull Bloomberg into a debate, where he could face real-time questions for the first time. Joe Biden had bristled at mentions of Bloomberg, saying that his money could not erase a record that the former mayor did not talk about. Elizabeth Warren and Bernie Sanders had both made specific criticisms of Bloomberg, with Warren saying the candidate had disqualified himself by blaming the end of housing segregation rules for the financial crisis, and Sanders pointing to Bloomberg's prior advocacy for a shrunken welfare state.

“It’s a shame Mike Bloomberg can buy his way into the debate,” Warren tweeted Tuesday. “But at least now primary voters curious about how each candidate will take on Donald Trump can get a live demonstration of how we each take on an egomaniac billionaire.”

For more on the ninth Democratic debate, and on the fights that could be finished onstage, look for a special edition Trailer tomorrow afternoon.

Candidate tracker

Seven of the eight remaining Democratic presidential candidates will spend tonight and tomorrow preparing for the Las Vegas debate, keeping them off the trail. That has given us a rarity: a campaign day when the president will be just as active as the Democrats.

Tulsi Gabbard. She'll hold an evening town hall in Colorado Springs.

President Trump. He'll hold a rally in Phoenix, the first in a three-state western swing.

Meet a PAC

THE PAC: Kitchen Table Conversations

PARTY: Democratic

FOCUS: As first reported by NBC News, it was formed a few days ago to run ads helping Amy Klobuchar build up name recognition in Nevada, South Carolina and Super Tuesday states.

BUDGET: It has enough donor commitments for at least $1 million in ad buys.

PLAN: Its first ad, “Sacred,” tells a foundational story in Klobuchar's career: giving birth to her daughter and being pushed out of the hospital at the 24-hour deadline. “It wasn't that long ago that hospitals did drive-by deliveries,” a narrator says, describing how Klobuchar campaigned to change that hospital policy. “Now they don't.”

EFFECTIVENESS: It's too early to say, though the super PAC nullifies something Klobuchar had been able to say just a week ago: that she did not have a super PAC helping out her campaign. (In the New Hampshire debate, Warren pointed out that only she and Klobuchar were running campaigns without personal wealth or “dark money” allies.) Super PACs have not done much good for Democrats in this cycle, with Cory Booker and Jay Inslee fading despite their outside spending, and the pro-Joe Biden “Unite the Country” super PAC unable to prevent embarrassing finishes in early states. But Biden started those races with strong name ID, unlike Klobuchar.

Countdown

... one day until the ninth Democratic debate
 … four days until the Nevada caucuses 
... seven days until the 10th Democratic debate
 … 11 days until the South Carolina primary 
... 14 days until Super Tuesday