The left is already looking to 2024. Some want to see a Biden primary challenge.

The fact that any primary challenge at all is now openly being discussed demonstrates how disappointed some progressives are about Biden’s presidency. It’s also a reflection of Biden’s weakness in the polls and his advanced age — the same factors that are driving more traditional and moderate Democrats to talk privately about scenarios if Biden doesn’t run for reelection as promised.

“I don’t think the country nor certainly not progressives in the party, who all tend to be younger, are going to sit on the sidelines,” said Mark Longabaugh, a progressive ad-maker who worked as a consultant for Sanders’ presidential campaign.

Weaver argued that a liberal challenge wouldn’t be a “repudiation” of Biden but rather the result of the Democratic Party moving left: “Progressives are ultimately ascendant. And if nothing else, a progressive running who gets a lot of support will demonstrate that the ideas that the progressive movement embraces are, in fact, popular.”

Though a progressive challenger would face an almost impossible task — despite his flagging poll numbers overall, Biden is still supported by the vast majority of Democratic voters — even a symbolic candidate could cause political trouble for the president.

If a left-winger primaries Biden, Trent predicted that “it’ll be a bigger primary than people anticipate — I think it’ll be like a Jimmy Carter primary.” Ted Kennedy, a liberal, won close to a dozen states during his 1980 challenge of Carter, who then went on to lose reelection.

When Sanders himself reportedly considered running against then-President Barack Obama ahead of his 2012 reelection campaign, the Obama team was alarmed because “every president who has gotten a real primary has lost a general [election].”

No candidate of Kennedy’s stature has even hinted at mounting a bid. “Progressives in the House, in the Senate, in the Progressive Caucus are not talking about primarying Biden,” said an aide to a senior House progressive.

If Biden did face a left-wing challenge, even from a lesser-known figure, it would mark a dramatic turnaround in his relationship with progressives. Though Biden was not their candidate — and liberals were deeply disappointed watching Sanders come close to winning the nomination only to falter — they have ended up being among the president’s staunchest allies. Top progressive aides helped elect Biden, and liberal House and Senate members have strongly defended his agenda in Congress.

“President Biden and his senior team have made a concerted effort to reach out to me since Sen. Sanders’ campaign ended and seek input into legislation and strategy,” said Rep. Ro Khanna, a former Sanders campaign co-chair. “He wants to implement a bold progressive vision, and he will have my enthusiastic support in 2024 so we have eight years to do it.”

Biden already looks to be trying to make amends with the left. Since Manchin axed Build Back Better, the president has acceded to two major demands from progressive lawmakers and activists: He extended the pandemic-related moratorium on student loan payments and recently offered his clearest and most direct support for doing away with the filibuster to push through voting rights legislation.

“The president and the full spectrum of the party are working to deliver on Build Back Better, including strong collaboration with progressives and the left,” said a Biden campaign alum.