Sen. Bernie Sanders (I-Vt.) and Sen. Elizabeth Warren (D-Mass.), who represent the Democratic Party’s more progressive wing, draw more frequent comparisons than any other 2020 primary candidates. News outlets have doggedly documented the two candidates’ subtle differences and, as Warren has climbed in opinion polls, have implied that her rise has come at Sanders’ expense. But the Sanders campaign does not see it that way. His aides argue that they are competing more heavily to win over voters who gravitate toward former Vice President Joe Biden, rather than Warren or any other candidate. Biden, the Sanders campaign believes, attracts the older working-class voters ― of all races ― with whom Sanders eventually gained traction in the 2016 election cycle. “Bernie appeals to younger working-class voters. Biden appeals to older working-class voters,” Ben Tulchin, the Sanders’ campaign’s chief pollster, told HuffPost. “The latter are some of the same voters Bernie won over last time. Our view is that we can win them back again, especially talking about his core economic message.” “When Bernie talks about a rigged economy propped up by a corrupt political system, that really resonates,” he added.

JIM WATSON/Getty Images Sen. Bernie Sanders (I-Vt.), right, sees older, working-class voters backing former Vice President Joe Biden, left, as ripe for persuasion.

In keeping with this approach, the Sanders campaign’s text messaging program has a specific response for voters who say they are supporting Biden. It also has a response for voters who say they are backing Sanders, but only a general response for cases where they say they are supporting any other candidate. The Sanders campaign, which claims to have sent 30 million text messages to voters, shared with HuffPost a text message that a volunteer sent a Nevada voter who said they were deciding between Sanders and Biden. “Thanks for letting me know!” the volunteer replied. “Did you know that Joe Biden told a room full of Wall Street billionaire donors that ‘nothing would fundamentally change’ if he became president? I’m for Bernie because he DOES think we need major change.” That pitch seemed to work. The voter eventually said they’d be backing Sanders. Biden did indeed tell a room full of wealthy donors that “nothing will fundamentally change” for them at a June fundraiser. His campaign maintains that Biden’s full remarks show he was saying that wealthy people would not need to give up their standard of living in order to enact policies that lift up all Americans.

Bernie Sanders Campaign Sanders' campaign has developed a specific text-message response for voters who say they're considering voting for Biden.

Whether one considers the volunteer’s texting appeal fair or not, it is a taste of the kind of contrast Sanders hopes to draw with Biden, who has deployed populist rhetoric about bridging the income gap but has often supported business-friendly policies and courted the party’s donor class over the course of four and a half decades in politics. (Neither Sanders nor Warren use private fundraisers to solicit big donations.) Trade is an area where Sanders believes he has a significant advantage over Biden with older working-class voters, particularly in industrial states like Iowa, a caucus state that hosts the first contest of the presidential primary on Feb. 3. Sanders voted against the North American Free Trade Agreement and permanent normal trade relations with China, which cost the United States blue-collar manufacturing jobs. Biden supported both. Sanders also opposed the Trans-Pacific Partnership, the now-defunct trade agreement that Biden promoted in his capacity as then-President Barack Obama’s vice president. Exit polling suggests that drawing a contrast with Hillary Clinton’s pro-free-trade record helped Sanders pull off a pivotal upset in the Michigan primary in March 2016. The campaign also sees Sanders’ plans to reduce the high cost of prescription drugs — which even voters on Medicare struggle to pay — and his long-standing support for expanding Social Security benefits as key selling points for older working-class voters. One of Biden’s main messages though, is that he’s the most electable candidate. He can win against Trump, he says, in part because he’s more moderate than Sanders and Warren. But Tulchin said voters concerned about electability tend to skew more educated and affluent, which are not the primary targets of Sanders’ class-centric message anyway. “The more upscale you go, the less well Bernie does,” he said. Tulchin emphasized that though Sanders believes he can win over some of the white working-class voters who voted for Obama in 2012 and subsequently switched to Trump, the campaign believes his message has appeal with working-class Black and Latino voters as well. The campaign is optimistic about Sanders’ chances in Nevada, where the disproportionately working-class Latino population makes up a large share of the electorate. (An average of public polls in the state nonetheless shows Sanders tied for second place with Warren.)

Brian Snyder / Reuters Some supporters of Sen. Elizabeth Warren (D-Mass.) are not considering voting for Sanders.

Tulchin told HuffPost that public polling data so far supports the campaign’s view that Biden voters have a similar socioeconomic profile to Sanders voters. In a national poll conducted by Monmouth University in late August, Sanders came in first place among Democratic voters without a four-year college degree, with 24% support. He was followed by Biden, who had 18%, and Warren, who had 17%. In the same survey, Biden and Sanders both had similarly high favorability ratings among both college-educated and non-college-educated voters, while Warren had a favorability rating with college-educated Democrats that was 20 percentage points higher than among those without a degree. (Sen. Kamala Harris of California and South Bend, Indiana, Mayor Pete Buttigieg enjoyed a favorability edge among college-educated voters at least as large as Warren’s.) In addition, Morning Consult’s national poll in late August shows that Biden supporters would pick Sanders as their second choice and vice versa. But the public opinion research is vast enough that other polls offer contradictory data. For example, a late August poll released by Quinnipiac University found that Sanders trails Biden among Democrats earning less than $50,000 a year, and lags behind both Biden and Warren among white voters without a college degree. And a Pew Research Center poll from mid-August found that more Biden voters would pick Warren or Harris as their second choice than would pick Sanders. Neither the Biden campaign nor the Warren campaign responded to a request for comment for this story. Over Labor Day weekend, HuffPost interviewed 35 voters at three Sanders rallies in New Hampshire and Maine; a Warren rally in New Hampshire; and a Labor Day breakfast in Maine hosted by local labor unions. There was plenty of affinity for Biden ― and Warren ― amongst the Sanders supporters. Of the 15 Sanders supporters with whom HuffPost spoke, voters cited Biden as their second choice just as frequently as they named Warren. (Some, though, were unwilling countenance a Sanders loss. Others named other second-choice candidates.)

His message is pretty much what the labor movement was, which is: power to the people, band together, take down corporations — or at least keep them in check. Wayne McAllister, Iron Workers Local 7