According to the Atlantic, Sanders and his team believe there is specific route for the senator to win the Democratic party's nomination.
Sanders believes he continues to have the strength in Iowa and New Hampshire to either win or come close there—especially, with other candidates fragmenting support and lowering the bar for what it will take to win. Likewise, in a South Carolina primary that has both Cory Booker and Kamala Harris competing for African-American votes and likely Joe Biden drawing on his own decades of connections there, Sanders sees a path to slip through and win.
In the years since the 2016 election, the Democratic party has moved consistently towards the left, aligning more and more with Sanders' pet proposals. Salon lists that many 2020 candidates have recently come out in support of—or at least hinted towards supporting—Sanders' Medicare for All plan. As his platform has become more popular, Sanders has become less unique in the party.
While his fellow Democrats haven't gone so far as to endorse his precise policy proposals, major candidates like Warren, Harris, O'Rourke and Sen. Cory Booker have offered at least rhetoric support for the concept. This reflects a growing awareness that the outspoken liberal wing of the Democratic Party cannot be taken for granted. Even if one questions the sincerity of some of these Democrats in their stance on that or other core progressive issues, all of them know that if they promise to deliver Sandersian policies as president and then fail to deliver, their party base will take them to task.
Sanders also has also maintained one of the most mobilized donor bases amongst Democratic presidential candidates. According to the New York Times, Sanders has 2.1 million individual online donors.
The findings provide a window into one of the most closely guarded and coveted resources of a modern campaign: the digital donor lists that bring in the vast bulk of low-dollar donations. These online donations average just under $40, and candidates like to point to such modest amounts as evidence of the breadth and depth of their support among regular people.
In the early stages of a presidential race, when polling measures little more than name recognition, the relative size of donor networks can provide one of the best metrics of strength.
However, the Sanders campaign has recently faced widespread allegations of sexual harassment and discrimination stemming from the 2016 election. GQ reports that when the candidate was asked about the accusations, he pushed back against them.
The report contained no allegations against Sanders himself, but his response came off as defensive and dismissive, and failed to really acknowledge his role in allowing such a culture to develop. “I’m not going to sit here and tell you we did everything right, in terms of human resources,” he told CNN’s Anderson Cooper. When Cooper asked if he knew about the complaints, he replied, “I was a little busy running around the country trying to make the case.”
Sanders' campaign has committed themselves to not repeating these problems in the future.
Jeff Weaver, Mr. Sanders’s 2016 campaign manager and currently a top adviser, said in an email that “anybody who committed harassment on the campaign would not be asked back” and expressed regret for the operation’s shortcomings.
“Was it too male? Yes. Was it too white? Yes,” he said. “Would this be a priority to remedy on any future campaign? Definitely, and we share deeply in the urgency for all of us to make change. In 2016, as the size of our campaign exploded, we made efforts to make it a positive experience for people. That there was a failure pains me very much.”
Others have simply grown tired of Sanders' brand of flip-flopping and refusal to work within the party system. Stephen A. Crockett Jr. writes at the Root:
Sanders is the kid that kicks it with the jocks but lightweight talks shit about them when he isn’t around them. He’s the drama kid that doesn’t want to be called a dramaturge in public. He caucuses with the Dems but then points out to anyone who asks that he’s an independent. At this point, I kind of want Sanders to have all the seats. I want Sanders to rent a bus and then sit in any seat he likes. Now would’ve been a nice time for him to sit his ass down and let a black woman handle this because she’s got it covered. It also would’ve shown that he is willing to play nicely with those in the party that he keeps wanting everything and nothing to do with.