By The Washington Post · Sean Sullivan, Michael Scherer · NATIONAL, POLITICS
Yet in just the past few days, the senator from Vermont has angered Florida Democrats with praise for Fidel Castro. He has upset some Jewish leaders with sharp criticism of a pro-Israel group. And his campaign has preemptively spurned billionaire rival Mike Bloomberg's offer to help fund his campaign in the general election.
These disputes with other Democrats, even as he cements a position atop the presidential primary field, are prompting nervousness and alarm among many of them over whether Sanders can set aside decades-old habits of combativeness and confrontation and bring the party together to take on a president they revile.
Steve Rabinowitz, a longtime Democratic Jewish activist, said he's puzzled that Sanders picked what he called an unnecessary fight with the American Israel Public Affairs Committee. "It runs so afoul of the politics that I have a really hard time understanding it," Rabinowitz said. "I know a lot of people who don't like AIPAC. I don't know a lot of people who cross the street to curse AIPAC. There is a persuadable middle, and we want them."
In a recognition of these fractures, Democratic leaders have begun saying openly that some down-ballot party candidates may run on non-Sanders positions if he is the nominee.
"It is not unusual for a party platform, or candidates for president, to have their own agenda they would put forth," House Speaker Nancy Pelosi, D-Calif., told reporters Thursday. "And it is not unusual for the House of Representatives to have its agenda to win as well."
Minutes earlier, Rep. Donna Shalala, D-Fla., spoke on the House floor in support of a bill condemning Sanders' comments praising Castro's literacy program, which she called "misguided, ill-informed, hurtful and unacceptable."
Adding to the Democratic anxiety, some are concerned about the small number of black voters among his audiences in South Carolina this week, suggesting he still may be struggling to attract that pillar of the Democratic coalition.
Jeff Weaver, a senior adviser to Sanders, dismissed the concerns, saying it is early in the process and that Democrats' loathing for President Donald Trump will ultimately bring them together.
"We're in the fourth of four early primaries," Weaver said, referring to Saturday's contest in South Carolina. "This party will come together, I guarantee it." He added, "Donald Trump is a great unifier in the Democratic Party."
The party's ongoing fractures came into vivid focus in Tuesday's Democratic debate, which showcased disagreements that might be hard for any nominee to resolve. For Sanders - a Democratic socialist who has spent a good deal of time attacking the Democratic Party and has never joined it - it could be doubly difficult.
As the magnitude of his Nevada victory was becoming evident last Saturday, Sanders signaled that he understood the challenge, and his speeches that day had an uncharacteristic focus on togetherness.
"We have news for Trump: Love and compassion and bringing people together is a lot more powerful than divisiveness," the senator said. He told supporters he was heartened by the "diversity and the beauty" of his audience.
Later that day, he gave a victory speech in San Antonio, where he sounded more than ever like a general election candidate.
"In Nevada we have just put together a multigenerational, multiracial coalition, which is not only going to win in Nevada - it is going to sweep this country," Sanders declared in raucous dance hall, where a sea of blue-and-white signs bearing his name bobbed up and down as his fans cheered him on.
That more inclusive pitch was no accident. Sanders, who is known to sketch out his thoughts on yellow legal pads, had spent the hour leading up to his speech in a holding room thinking about his remarks, according to an aide with knowledge of his activities, who spoke on the condition of anonymity to discuss internal matters.
Gone were the taunts against the "Democratic establishment," which for weeks had been surefire applause lines. Instead, Sanders has aimed his fire since then at Trump and the "establishment" in general - a subtle but unmistakable shift - as well as the news media.
"Every speech he gives, he talks about his concerns with 'the establishment,' " said Sanders campaign manager Faiz Shakir. "But that said, you do see efforts on our part to try to bring people into this tent."
In recent days, Sanders has seemed equally intent on keeping unwelcome visitors out of the tent. His comments suggest he is not entirely sold on the strategy of moderating the aggressive posture that has powered his career and his current rise.
In a "60 Minutes" interview that aired Sunday on CBS, Sanders said the late communist leader Fidel Castro leader deserved criticism for "the authoritarian nature" of his regime in Cuba but also merited praise for enacting "a massive literacy program."
That prompted an eruption from some Democrats in Florida, a crucial swing state that is home to many Cuban exiles. Democrats would face a challenge in winning Florida regardless, but Sanders' comments likely made it harder.
The Florida Democratic Party took the rare step of issuing a statement against a leading presidential contender, warning that "candidates need to understand our immigrant communities' shared stories."
Sanders did not back down. "When dictatorships, whether it is the Chinese or the Cubans, do something good, you acknowledge that. But you don't have to trade love letters with them," he said during Tuesday's debate, a reference to Trump's correspondence with North Korean leader Kim Jong-Un.
Annette Taddeo, a Democratic Florida state senator who was born in Colombia, compared Sanders' words to Trump's 2017 comments about a deadly white supremacist rally in Charlottesville, Virginia.
"Saying a murderous dictator wasn't so bad because of a literacy program is like saying 'there were very fine people, on both sides,'" she wrote on Twitter.
She said Sanders' refusal to disavow his past praise of the Cuban regime is a barrier to party unity.
"The thing that he shouldn't have done is double down - that makes it a lot harder now," said Taddeo, who would not commit to voting for Sanders if he is the nominee. "I am having heartburn right now."
That is not the only foreign policy issue that has rankled some activists. On Sunday, Sanders issued a sternly worded statement about the American Israel Public Affairs Committee, or AIPAC, a group with which he has long been at odds, and which is hosting a conference this weekend.
"The Israeli people have the right to live in peace and security. So do the Palestinian people. I remain concerned about the platform AIPAC provides for leaders who express bigotry and oppose basic Palestinian rights. For that reason I will not attend their conference," Sanders wrote on Twitter.
That drew immediate scorn from Jonathan Greenblatt, a former Obama administration official and current head of the Anti-Defamation League, who called the comments "offensive and irresponsible."
Sanders was the focus of relentless attacks from his rivals at Tuesday's debate on a range of issues, and he did not hesitate to hit back. In the eyes of many voters, the contentious two-hour session was a snapshot of party that is far from ready to put its differences aside.
"I just felt like there was a lot of animosity," said Jean Read, 60, a retired educator who is leaning toward Sanders in Saturday's South Carolina primary but also likes Sen. Elizabeth Warren, D-Mass. "I think they will unify once a candidate is chosen, but right now I think it's a dog-eat-dog fight."
For many Sanders supporters, his steadfast commitment to his beliefs and his unwillingness to modulate is precisely what makes him appealing. They were heartened by Sanders's refusal to recant his comments on Cuba and Israel.
Sanders is arguably most effective when he has a foil to rail against. In his 2016 and 2020 presidential runs, that has included not just wealthy corporations but the Democratic Party.
The question now is whether he can break that habit, whether he wants to, and even whether it's advisable. Trump, after all, never took the GOP establishment off his list of targets in 2016, and that did not stand in the way of his winning the nomination.
Rep. Ro Khanna, D-Calif., a national co-chair of the Sanders campaign, said the senator "will run as the underdog until he's the nominee, and he will run as the underdog until he's president."
The Sanders campaign has shown little appetite to build bridges with Bloomberg, who has vowed to put his personal fortune behind the eventual Democratic nominee even if it's not him.
Weaver, the Sanders adviser, told NBC News that Sanders does not want Bloomberg's assistance, prompting Bloomberg adviser Howard Wolfson to suggest the offer could be rescinded. "I don't think it would be prudent to spend on behalf of somebody who didn't want it," Wolfson said.
Kevin Sheekey, Bloomberg's campaign manager, said Thursday on MSNBC that it would be a blunder for Sanders to reject the help. "I think Senator Sanders makes a grave mistake if he thinks he can go this alone," Sheekey said.
Sanders has attacked Bloomberg as a billionaire trying to buy the election.
"We don't need billionaire help to win this election. We've got the people!" Sanders shouted at a rally here Thursday as the crowd roared its approval.