What’s gotten into Sen. Bernie Sanders? On Sunday, Geoffrey Skelley noted that, according to FiveThirtyEight’s forecast of the Democratic presidential primary, the Vermont senator had shot up to a 1 in 4 chance (26 percent) of winning a majority of pledged delegates. Now, as of Tuesday evening, Sanders’s chances are up to 3 in 10 (31 percent) — that’s a 5-point jump in just 48 hours! That’s easily the best chance our model has given Sanders to date.

[Our Latest Forecast: Who Will Win The 2020 Democratic Primary?]

With a 2 in 5 (41 percent) shot of winning a majority of pledged delegates, former Vice President Joe Biden still leads our forecast overall, but there’s now far less room separating him from Sanders. However, the gap between them is still significant — a 30 percent chance that something will happen is, mathematically speaking, a lot different from a 40 percent chance. Sen. Elizabeth Warren and former South Bend, Indiana, Mayor Pete Buttigieg, on the other hand, might be in real trouble: Their chances have been steadily declining to the point where their odds of winning a majority of pledged delegates are now just 1 in 15 for Warren and 1 in 20 for Buttigieg. By way of comparison, as recently as Jan. 10, Warren had a 1 in 8 shot, and Buttigieg sat at 1 in 10.

Warren and Buttigieg are doing better in Iowa, but it does seem as if in recent days, the first-in-the-nation caucus state has become more of a two-way race. Our model currently gives Sanders the best odds of winning the most votes there (a 2 in 5 chance, or 37 percent), followed closely by Biden (1 in 3, or 35 percent). And two recent polls have helped buoy Sanders’s chances, putting the Vermont senator in the lead in Iowa. However, both surveys were from pollsters that tend to show fairly strong results for Sanders, so those leads may not be as wide as they seem:

On Sunday night, we got an Emerson College poll of Iowa that put Sanders at 30 percent and Biden at 21 percent (followed by Sen. Amy Klobuchar at 13 percent, Warren at 11 percent and Buttigieg at 10 percent). However, Emerson has shown good numbers for Sanders all cycle relative to other pollsters, so, after adjusting for house effects, our model treats that as Sanders having hit 24 percent and Biden as having hit 20 percent. (So this poll still represents a Sanders lead, but his lead isn’t quite as large.) The poll was nonetheless an improvement for Sanders over Emerson’s previous Iowa poll, from early December, which put Biden at 23 percent and Sanders at 22 percent.

And on Tuesday, Change Research put out a new poll showing Sanders at 27 percent, Buttigieg at 19 percent, Biden at 18 percent and Warren at 15 percent in Iowa. However, Change polls have also tended to overestimate Sanders and underestimate Biden, so our model treated this as more of a virtual tie between Sanders and Biden, giving them about 22 percent apiece in the model.

New Hampshire, on the other hand, is beginning to drift out of the “competitive” column. According to our model, Sanders currently has a 1 in 2 (49 percent) chance of winning the most votes in the Granite State. The next-likeliest victors are Buttigieg and Biden, but both are pretty far behind with only a 1 in 5 chance. And of the two new polls of New Hampshire we’ve gotten so far this week, both held very good news for Sanders, especially given the fact that neither have particularly strong house effects:

According to a Franklin Pierce University/Boston Herald/NBC10 poll conducted by RKM Research and Communications, Sanders now sits at 29 percent in the Granite State, with Biden at 22 percent, Warren at 16 percent and Buttigieg at 10 percent. That represented a 7-point gain for Sanders over the same pollster’s findings just two weeks ago. Again, Biden (down 4 points), Warren (down 2 points) and Buttigieg (up 3 points) experienced less dramatic changes.

And in its first New Hampshire poll of the cycle, American Research Group gave Sanders a very impressive lead. He has 28 percent support in the poll, while no other candidate has more than 13 percent.

We also got three new national surveys of the Democratic primary on Monday and Tuesday, although their numbers were not as good for Sanders as the state polls, as Biden was still the leader in all three polls.

Of the three, Echelon Insights painted the best picture for Sanders: Biden garnered 26 percent support — down 11 points from the firm’s December poll — while Sanders nearly matched him at 23 percent — up 9 points from December. (Notably, former New York City Mayor Michael Bloomberg was the one who finished third in Echelon’s poll, with 13 percent — however, our model is still skeptical about his chances overall because he is not contesting the first four states, but his unorthodox campaign strategy also makes him hard to forecast.) But considering Echelon has historically had fairly high numbers for Biden, the fact that Sanders almost caught him is at least somewhat noteworthy.

According to Quinnipiac University, Biden now has 26 percent support nationwide, while Sanders is in a solid second place at 21 percent. However, on the downside for Sanders, Quinnipiac hasn’t observed much movement in the past two weeks, as its Jan. 8-12 survey put Biden at 25 percent and Sanders at 19 percent.

Finally, the latest installment of Morning Consult’s weekly poll found Biden at 29 percent and Sanders at 23 percent. That’s virtually unchanged from their last poll, conducted Jan. 15-19, that put Biden at 29 percent and Sanders at 24 percent. (However, Morning Consult also has a pretty large pro-Biden house effect, so it’s not necessarily that great of a finding for Biden.)

Finally, it’s worth noting Sanders’s strength in Nevada. We haven’t seen a poll of Nevada in the last couple weeks, but based on the fact that Sanders now has a good shot at winning both Iowa and New Hampshire, our model now puts him on track to win the Silver State. He currently has a 1 in 2 (45 percent) chance to win the most votes in Nevada, a fair bit ahead of Biden, who — at odds of 1 in 3 (34 percent) — is in second place. However, Biden remains a solid favorite in South Carolina, with a 3 in 5 (62 percent) chance of prevailing. By contrast, Sanders has a 1 in 4 (27 percent) chance.

In other words, our model now thinks that Sanders has a good chance to win the first three states to vote this primary season. However, Biden remains the more likely candidate to win a majority of pledged delegates nationally. So the question is, if Sanders does succeed in winning Iowa, New Hampshire and/or Nevada, will he get enough of a polling bounce to knock Biden off that perch? Or will Biden hold on and make a comeback in South Carolina — or maybe even earlier? Remember, Iowa is far from settled.





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