The poll numbers for his presidential candidate are stubbornly mired in the single digits. The fundraising numbers are equally underwhelming. Still, the Democratic strategist makes a detailed, optimistic case for patience, one anchored firmly in recent history. “Seventy percent of the electorate doesn't have a favorite yet, and people are going to have fatigue about the current frontrunners. You see it with Kamala Harris—she had this crazy amazing first week, and then she’s leveled off,” he says. “Everyone in the field is going to get a look, from voters and from the media. That’s what happened to the Republicans in 2016 when they had 17 people in the field—Carly Fiorina had a moment. Herman Cain had a moment, for God’s sake. So we’re going to get a look.” Then he sighs. “But, yeah, Bernie is definitely a problem.”

The Democratic establishment fear of Sanders started percolating in February when he raised $6 million in the first 24 hours after officially announcing his 2020 run. It escalated into borderline panic in the past few weeks, as Sanders dominated the first-quarter money race, hauling in $18.2 million, and as his polling numbers stayed healthily, steadily solid, in the high- to mid-20s. Part of the reason for his strong start is the nimble digital operation Sanders built during his 2016 run against Hillary Clinton. A greater part is his distinctive theory of the case. “It’s called having a message,” says Cornell Belcher, a pollster for both of Barack Obama’s presidential campaigns. “He has a clear vision of how the economy and the government should work. You may agree or disagree with Bernie’s policy ideas, but in this field his message is the most deeply developed, while the others at this point are kind of fuzzy.”

Sanders is making more of an effort to connect with voters on a personal level: at the Reverend Al Sharpton’s convention in New York recently, Sanders tried to bond with the predominantly black audience by talking movingly about how he understood bigotry and persecution because “I am the son of immigrants whose family was murdered by the Nazis.” Yet the core of Sanders’s appeal centers on Medicare for All and rebalancing the economic playing field away from the one percent, just as it did in 2016. Moderate Dems are scrambling to develop alternatives: Senators Chris Coons and Michael Bennet are touting “Medicare X,” which sounds like the name of the worst Netflix series ever, but is a plan to offer a public option as well as private insurance. Other people are just freaking out: Larry Summers raised the specter of a Sanders nomination as the second, disastrous coming of George McGovern in 1972, and the Center for American Progress, a Clinton-friendly think tank, handed Sanders a gift by attacking him as a millionaire hypocrite. Sanders quickly exploited the episode to bolster his outsider cred, though re-litigating 2016 runs the risk of making Sanders look as if he has a martyr complex. “I mean, Bernie wrote a letter in response, then leaked it to the Times!” a top strategist for a Democratic contender says. “That wasn’t some shit that just happened, like an angry phone call.”

Even without the perverse help, Sanders wasn’t going away anytime soon. “I thought Elizabeth Warren’s entrance into the race would greatly eat into Bernie’s numbers because she has an appeal to the same constituency,” says Ben LaBolt, an Obama White House strategist. “His support is looking fairly durable. This could shape up into the field versus Bernie.”