EL PASO — On one side of the room, at the back of Bally's casino, Michael Bloomberg’s top strategist speculated with reporters about not if, but perhaps when, they would spend millions on negative ads against the Democratic frontrunner.

“Campaigns are fluid and we'll see…”

Across the ballroom in Las Vegas, where officials from each campaign gathered earlier this week after the latest debate, a Bernie Sanders official responded with an impassive shrug. “So let them,” the candidate’s closest and longest-serving adviser Jeff Weaver said, as he turned for the exit without stopping.

It was a typical flash of bravado from the 78-year-old senator’s campaign. But for the rest of the Democratic presidential field — as other candidates have begun talking openly about who among them is best positioned to stop the Vermont independent — Weaver's challenge captured a building sense of seemingly inexorable forward-movement by Sanders ahead of the most critical juncture in the race.

Three days later, on Saturday afternoon, Sanders won the caucuses in Nevada, the third state on the primary calendar and the first to reflect the kind of diverse electorate that will vote across 16 states and territories on March 3 and determine one-third of the party delegates required to clinch the nomination.

As the vote came in on Saturday afternoon, Democrats watched to see which candidate would win the race for second place. But Sanders’s apparently decisive Nevada victory has set up an immediate and existential moment in the nominating process: In just 10 days, Sanders could emerge from Super Tuesday with a delegate lead that other candidates can chase but never reach.

It is one of the surest, most unyielding rules in presidential politics: Once one candidate has a sizable delegate lead, it becomes difficult — at first increasingly improbable, then mathematically impossible — for another to catch up.

It was true in 1980, with Jimmy Carter. It was true in 2008, with Barack Obama. And it was true four years ago, during Sanders’s first presidential campaign, with Hillary Clinton. In March of 2016, she emerged from Super Tuesday ahead by more than 160 delegates — enough to build a permanent advantage. If he wanted to surpass her campaign, Sanders wouldn’t just need to start winning more states — he would have to start winning everywhere, by significant margins.

He could keep running — and he did, until the Democratic convention — but he never had much chance to win.

Now, as the remaining candidates fight for a commanding position in the race before the 14-state contest in 10 days, Bernie Sanders is on the other side of the delegate math.

“If he has a three-figure lead, there is no catching up,” said Robby Mook, Hillary Clinton’s campaign manager in 2016. “It’s too late after Super Tuesday. Even if the field drops down to two people, that person still has to be beating him by 10 to 20 points in the remaining contests.”

“This is the fog everybody is in right now. If you aren’t Sanders,” Mook said, “you have to deal with this problem before Super Tuesday.”

David Plouffe, who was Barack Obama’s campaign manager in 2008, said on MSNBC Saturday night that if the primary stays crowded after Super Tuesday, Sanders could have a hold on the nomination.

“If it is more than a two-candidate race, certainly — if it’s a four or five-candidate race, Bernie Sanders can walk to the nomination getting 35, 36, 37% of the vote,” he told NBC’s Brian Williams.

He later made that more explicit. “But basically, if we’re — Brian, if it’s March 3 and we’re talking about Klobuchar, Buttigieg, Warren, Biden, Bloomberg, and Sanders, and everybody’s in, Bernie’s going to win almost all the delegates he needs to build an impenetrable delegate lead. That’s just math. It’s not my opinion — it’s just simple math."

On Saturday morning, hours before the start of the caucuses in Nevada, Sanders was already on his plane, bound for Texas, one of the largest Super Tuesday states. He arrived in El Paso, the first of four cities he will visit here this weekend, to greet an outdoor overflow crowd and a full house at the Abraham Chavez Theatre, which seats 2,500 people.

Early voting is already underway in California and Texas, states that will decide 643 of the 1,991 total delegates needed to win the Democratic nomination at the convention. In Nevada, a similarly diverse state where Sanders has excelled with Latinx voters, he is projected to have won the support of 51% of Hispanic Democrats in CNN’s entrance poll, as well as a quarter of black Democrats.

“When I look out at an audience like this and I see the diversity and the beauty in this audience — and let me tell you, you do look beautiful from here,” said Sanders, a rare grin on his face as he began his speech in El Paso. “I feel absolute confidence that we can create a government that is based on compassion that is based on love, is based on truth, not what we have now of greed, corruption, and lies.”

His position in the race has only recently invited attacks and attention from his rivals. For months, Democrats largely ignored, dismissed, or even praised Sanders as a consistent and well-meaning politician who represented a wing of the party too marginal to decide a nomination. Now, Pete Buttigieg is telling voters that his nomination would amount to “a fatal error.” Elizabeth Warren is calling on his campaign to release more medical records. And Joe Biden is drawing attention to his reversed positions on gun control.

Earlier this week, officials working for Bloomberg outlined the delegate outlook on Super Tuesday based on their own internal polling, warning Democrats that if the field of eight candidates did not narrow before early March, Sanders would be “impossible to stop.”

A starkly worded memo, published by Axios on Wednesday, estimated that Sanders could amass a delegate lead of more than 400 in the March 3 states and argued that, with “no path” to the nomination, the other leading candidates should step aside for Bloomberg or guarantee a Sanders victory. Some Democrats balked at the memo as bald arrogance — a billionaire former Republican pronouncing such candidates as Biden and Warren dead and “crumbled” — but Sanders does stand to make it increasingly difficult for any one candidate to break out from the field and reduce his lead.

“People either functionally or actually need to get out of the race before Super Tuesday,” said Addisu Demissie, a veteran operative who managed Cory Booker’s presidential campaign and worked as a senior Clinton aide in 2016. “Otherwise, Sanders is going to open up a lead and, quite possibly, one that is too big to close.”

In the Democratic nominating process, candidates who hit a 15% threshold in a given state or district receive delegates proportionally — a number that could become even more significant in a field where multiple candidates split smaller portions of the vote below 15%. “We typically think of the threshold issue as pushing people out [who don’t hit 15%], but it also buttresses the people making it in,” said Mook.

Howard Wolfson, Bloomberg’s chief strategist, forecast the next 10 days as a “battle royale among the moderates to see who is best able to position themselves against Sanders."

“It seems to me incumbent upon those of us who understand the challenge that Bernie Sanders would present at the top of the ticket to figure it out,” he told reporters in Las Vegas.

Sanders has never pursued a typical path to the Democratic nomination.

He is a longtime registered independent who criticizes the Democratic establishment he seeks to lead. He rarely discusses politics through the lens of the party unless he is decrying it. He has both sued the Democratic National Committee, accusing its chairperson in 2016 of knowingly “rigging” the nomination in favor of Clinton, and served in the four years since as one of its top surrogates, most prominently on a multistate “unity” tour in 2017.

In his first presidential campaign, Sanders openly attacked superdelegates — the party leaders and elected officials who have historically had a say in the Democratic nominating process — before launching a last-ditch campaign to win their support when he fell behind Clinton with voters.

Early on in his second campaign, Sanders advisers were already describing their path to the nomination as fractured: In a large field, they said, Sanders could win the most delegates with just “a third” of the vote — setting up the possibility of a contested national convention this summer.

“We can win the Texas primary,” the candidate said to cheers in El Paso on Saturday as caucus results were still coming in. “We can win the Democratic nomination. We can defeat Donald Trump. And we can transform this country. Let's do it!”

Sanders didn’t mention Nevada.



He was on to his usual stump speech, standing before a giant Texas flag.