sanders nevada caucus
© Drew Angerer / Getty Images
Sen. Bernie Sanders and his wife Jane Sanders at Cowboys Dancehall in San Antonio, Texas, after winning the Nevada caucuses.
Bernie Sanders has won the Nevada caucuses, and it looks like he's going to win them by a big, perhaps even landslide margin.

We don't know exactly how big. As I'm writing this just before 7 p.m. Las Vegas time, only a relatively small percentage of precincts have officially reported results. Nor do we know who's going to wind up in second place, although it will probably be either Joe Biden or Pete Buttigieg.

Unless the final margin unexpectedly tightens, though, I don't think the details are going to matter that much. This was a big, impressive win for Sanders, and it should be even clearer now that Sanders is easily the most likely Democrat to win the nomination.

projected results nevada caucus
© ABCNews
ABC News projection of Nevada Democratic caucus results
Unlike in Iowa and New Hampshire, there aren't really any qualifications or caveats about Sanders's victory here. Nevada is a diverse state, and Sanders did well among a broad array of demographic groups, including winning 53 percent of Hispanics and 27 percent of African Americans, according to the entrance poll. This is a pretty good electorate for Sanders: young, working-class, unionized, heavily Hispanic. But he's also worked hard to cultivate support from those groups of voters — Hispanic voters weren't a major strength of his in 2016 for example. Perhaps fortunately for him, there are also plenty of these types of voters in the two biggest delegate prizes on Super Tuesday, California and Texas.

In addition to being the most likely winner overall, Sanders is by far the most likely Democrat to win the nomination with a majority of pledged delegates. Other candidates are mostly hoping for a messy outcome in which they win the nomination by plurality — potentially at a contested convention.

We don't have enough results as of this writing to officially update our forecast model, but the first two of these prebaked scenarios we built should give you a rough idea of what it will say:

How Nevada could affect the nomination odds

Chances of winning a majority of all pledged delegates based on winner, margin of victory and second-place finisher in Nevada, according to FiveThirtyEight's forecast:
nevada causcus projected results
© FiveThirtyEight
We’re defining a “narrow” win as anything less than 4 percentage points over the second-place candidate, a “medium” win as 4 to 12 percentage points, and a “large” win as more than 12 percentage points. Scenarios are only listed if they had at least a 1 percent chance of occurring.
That is, Sanders will probably be somewhere in the vicinity of an even-money bet to win the nomination with a delegate majority. He will presumably also be the nominee by plurality at least some of the time that nobody wins a majority. (The model will likely show around a 35 or 40 percent chance of there being no majority.) That means Sanders is probably more likely than not to be the nominee, whether by majority or plurality, although note that our model doesn't try to forecast what would happen in the event of a contested convention.

After Sanders, the candidate with the next-best puncher's chance at winning via the majority route is probably Biden. Nevada is his best result so far which — yes — is extremely damning Biden with faint praise after a 4th place finish in Iowa and a 5th place finish in New Hampshire. But it looks like Biden at least found a bottom and will match or slightly exceed his polls in Nevada, unlike in the first two states. He also did win some key groups in the entrance poll, such as African-Americans and seniors.

Obviously, Biden would need to win South Carolina for a comeback to be a real possibility. (With a South Carolina win, his majority chances would likely improve to somewhere in the neighborhood of 20 percent in the model.) Biden does still lead in the polls in South Carolina, but it's a narrow lead, and the question is whether any further bounce that Sanders gets from winning Nevada will be enough to propel him into first place. There are a lot of other contingencies in South Carolina, also, including a debate next week, and what Tom Steyer will do after a poor finish in Nevada. It's still possible that we wind up with a Sanders-Biden faceoff for the nomination, though — albeit one where Sanders probably has the advantage.

So what about everyone else?

Buttigieg has been the second-best performer in the first three states, after Sanders. But neither his (disputed) win in Iowa nor his strong second-place finish in New Hampshire produced much of a polling bounce, so there's no particular reason to expect a distant second or third place finish in Nevada to do so either. And Buttigeg needs a bounce, because he's at best flirting with the 15 percent viability threshold in South Carolina and in Super Tuesday states, and often polling below it. That's not to say Buttigieg is out of the running, but his wins largely involve the long, protracted plurality and/or contested convention route, and not winning by majority.

Meanwhile, Michael Bloomberg still looms over Super Tuesday, although maybe he doesn't loom so large after this week's debate. The model still gives him an outside chance at a majority and decent chances of a plurality. But there's been little post debate polling and his position may decline as more of it comes in; initial results should be a bit concerning for Bloomberg.

Elizabeth Warren's finish was disappointing tonight — but her campaign will undoubtedly claim they were done in by early voting, which took place before last week's debate. As of this writing, we don't really have enough data in to comprehensively evaluate that claim, although she did win 17 percent of late-deciding voters in the entrance poll, somewhat stronger than her overall finish.

Finally, there's no particular reason to think that Amy Klobuchar or Steyer have a way forward. And Steyer's poor finish, likely to be in the single digits after investing millions of dollars in advertising and other resources in Nevada, is an inauspicious omen for Bloomberg.

We'll let you know once we have enough data to turn the model back on. In the meantime, though, the headline is pretty simple: This was a great day for Sanders.