She doesn’t poll her audience for people from Massachusetts, where she is the senior senator and where she has lived for over 20 years. Nor does she refer to herself as a “professor,” instead saying that after a brief public school-teaching stint she “traded littles ones for big ones and taught in law school for most of my life.” At times on the trail, she wears a Berkshire Community College cap — supporting the small school in western Massachusetts where she gave the commencement address in 2015.

Behind the scenes, however, the detailed plans that are the centerpiece of her campaign, covering everything from a wealth tax to trade deals’ “Investor-State Dispute Settlement,” were crafted by an elite Ivy League-studded policy team, whose four members and a senior outside adviser all carry degrees from Harvard University or Yale University as of this summer.

Her policy team’s reliance on Ivy Leaguers, along with the Harvard Law School alumni she regularly consults, reflect the duality in her campaign — the fact that Warren is both an up-by-the-bootstraps success story and a privileged Ivy League professor — that opponents are starting to notice and exploit.

“It’s representative of an elitism that working and middle class people do not share: ‘We know best; you know nothing,’ ‘If you were only as smart as I am you would agree with me,’" Joe Biden wrote in a Medium post this week, referring to Warren’s “viewpoint.”

Biden’s decision to go on the attack reflects Warren’s success in building a base of support as large or larger than his in the first two nominating states of Iowa and New Hampshire, according to polls. But his chosen line of attack — her alleged elitism — replicates one that Republicans have tried, with varying success, over the years.

Indeed, a strategy memo prepared by her opponent in the 2012 Senate race, former Republican Sen. Scott Brown, and obtained by POLITICO advised focusing squarely on her Ivy League background: “Professor Warren is an out-of-touch elitist whose ideas are informed by two decades on the campus of Harvard, but don’t work in the real world.”

Brown campaign focus groups showed voters divided on whether they found Warren a sincere champion for the less privileged, the memo reported. “Some believe she is phony because she doesn’t live in the same world as they do,” the campaign wrote, summing up the survey results. “Others cite her background as justification of her advocating for the middle class.”

“Every day, the message was elitist, elitist, elitist,” an official from Brown’s 2012 campaign recalled of their strategy.

On the campaign trail, Brown referred to her as “Professor” and “Professor Warren” at every opportunity. His campaign spokesperson said Warren "is firmly entrenched in the same ‘1 percent’ she rails against.” The Brown team demanded she release a full list of the corporate clients she advised with hundreds of thousands of dollars in compensation. And Brown said her $300,000-plus salary at Harvard was demonstrative of loose spending at colleges that had driven up tuition rates.

Warren’s response to the charges, made at their first debate, offers a window into how she might deal with the elitism issue in a future general-election campaign for president: She portrayed herself as an only-in-America success story, adding she was motivated to run for office because she thought the opportunities she had were less available to today’s young people aspiring to improve themselves.

“So, my first teaching job in law was — I made $18,070, and I’m proud of the fact that I’ve made it to one of the top spots in teaching,” she responded when Brown criticized her Harvard salary.

Warren beat Brown by 7 percentage points despite exit polls showing him with a 60 percent favorability rating. She also ran 7 points behind President Barack Obama in Massachusetts, meaning many Obama voters also voted for Brown.