Read: Elizabeth Warren has momentum. Can she build a movement?

According to polls at the time, voters considered Clinton more electable than Obama, a point she highlighted in her own Jefferson-Jackson speech, when she promised, “I know what it’s going to take to win.” She also stressed her greater experience. “We must nominate a nominee who has been tested,” she told the Iowa crowd, “and elect a president who is ready to lead on day one.”

But many Democrats resented Clinton’s vote for the Iraq War. And at a debate on October 30, she had repeatedly refused to give a straight answer when asked whether undocumented immigrants should be able to get driver’s licenses. So when Obama took the stage at the Jefferson-Jackson dinner, he exploited a sense among Iowa Democrats that Clinton lacked political courage, and that a vote for her would reflect their own lack of courage, too. “Not answering questions ’cause we are afraid our answers won’t be popular just won’t do,” he told the crowd. “Triangulating and poll-driven positions because we’re worried about what Mitt [Romney] or Rudy [Giuliani] might say about us just won’t do. If we are really serious about winning this election, Democrats, we can’t live in fear of losing it.”

The response was extraordinary. Obama, reported Time magazine, “has found his voice.” The Des Moines Register’s influential political reporter David Yepsen wrote that “should [Obama] come from behind to win the Iowa caucuses, Saturday’s dinner will be remembered as one of the turning points in his campaign.” By early December, according to Iowa polls, Obama had taken the lead.

There are obvious differences between Warren now and Obama then. Obama was more frequently attacked for his lack of experience; Warren is more often criticized for being ideologically extreme. Obama also enjoyed a greater reservoir of potential African American support. After he won Iowa, black voters moved to him en masse, which laid the foundation for his victories in the South. If Warren wins Iowa, she’s unlikely to benefit from the same decisive shift.

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Still, there are enough similarities between Obama’s position in the fall of 2007 and Warren’s in the fall of 2019 to see why adopting his “Don’t be scared” message could work. Biden has an even longer record than Clinton of taking positions that make contemporary Democrats cringe. And, like her, he’s relying on Democrats’ belief that he can win a general election—and be a steady hand once in office—to overcome their lack of enthusiasm. In his speech to New Hampshire Democrats, Biden mentioned Donald Trump in his first sentence. “We cannot and I will not let this man be reelected president of the United States of America” was his biggest applause line. But despite this, according to The New York Times, Biden “received a polite though not raucous reception.”