Bernie Sanders is quick to slam Joe Biden's past support of free trade deals and the Iraq War. He is warning him against a "middle ground" approach to addressing climate change. His campaign sends fundraising appeals with a simple, foreboding subject line: "Joe Biden." In his nearly three weeks as a presidential candidate, Biden has become Sanders' favourite foil.
No one seeking the 2020 Democratic presidential nomination has been as aggressive as the Vermont senator in highlighting episodes from the former vice president's past to sow skepticism in the party's progressive base.
The strategy is reminiscent of Sanders' approach to the 2016 Democratic primary, when he relentlessly slammed Hillary Clinton as an establishment pawn. And it's a reminder that, even when Sanders lags in the polls, he is often most comfortable when he's taking on top Democrats, hoping that such attacks will energize his most loyal supporters.
That was easy to do in 2016 when he was the sole outsider candidate taking on one of the most recognizable names in Democratic politics. It could be tougher now that he's a leading contender for the nomination who has spent the past several years building an organization to support his candidacy.
"Bernie is trying to rekindle the magic of 2016, where he was the outsider running against a longtime member of the establishment," said Dan Pfeiffer, a former senior adviser to President Barack Obama.
"The challenge is that this year there are no candidates with a claim to outsider status." A Sanders representative declined to comment. Mark Longabaugh, an adviser to Sanders' 2016 campaign, said the senator ran then by pitting himself first and foremost against "Wall Street, pharmaceutical drug companies and the Koch brothers," who funded conservative causes and campaigns.
Sanders' critiques of Biden come as the former vice president is taking the lead in many polls, displacing Sanders from the top.
For his part, Biden only nods at the tensions without mentioning Sanders by name. Campaigning in New Hampshire this week, Biden defended his record as progressive, particularly on environmental and health care policies. He pushed back at a news report that he was considering a "middle ground" on climate policy that prompted stinging criticism from Sanders and Democratic Rep. Alexandria Ocasio-Cortez of New York.
"I was in this area long before most anybody else was, and I have a record," he said, calling himself "a leader in climate change" and referring to a 1987 Senate floor speech during which he referred to a warming Earth as an "existential threat."
Zac Petkanas, a Democratic strategist who served as an adviser to Clinton's 2016 campaign, said Biden has the luxury of ignoring Sanders' attacks as the race right now appears to be "Joe Biden versus about 20 other candidates."