The announcement of Cornel West’s third-party run for the presidency has sent shockwaves through the Democratic Party. West, a prominent philosopher, Ivy League academic, and leftist, recently announced that he is newly registered with the Green Party as he seeks to challenge Joe Biden and the eventual Republican nominee for the White House. This move has caused anxiety among some prominent figures supporting Biden, from the head of the Democratic National Committee to veteran campaign hands, who are already sounding the alarm about his quixotic White House run.

The concerns about West’s third-party run come as Democrats prepare for the 2024 presidential election, with many already worrying about the potential impact of his candidacy on Biden’s reelection bid. Seven years ago, when Hillary Clinton lost to former President Donald Trump, many in her orbit blamed Green Party nominee Jill Stein as a factor that contributed to her defeat. Heading into 2024, Democrats worry West could emerge as a similar spoiler by earning just enough votes to fracture the coalition Biden needs to win.

“In 2016, the Green Party played an outsized role in tipping the election to Donald Trump,” wrote David Axelrod, who served as former President Obama’s chief strategist, on Twitter. “Now, with Cornel West as their likely nominee, they could easily do it again. Risky business.”

The Democratic Party is not taking West’s third-party run lightly. DNC Chairman Jaime Harrison, a close Biden confidant, warned over the weekend that “this is not the time in order to experiment. This is not the time to play around on the margins.” Harrison’s comments reflect the growing anxiety among Democrats that West’s candidacy could hurt Biden’s chances of winning the presidency in 2024.

Some progressives close to West want him to agitate Biden further. They’d like to see him debate the president but concede there’s a slim chance of that happening. Biden “risks the same thing that scared the hell out of neoliberals in 2016,” said Nina Turner, a staunch progressive and former state senator from Ohio who worked with West on Sanders’s last campaign. “The ideas of the progressive left are popular with the majority of the American people,” she said, suggesting West has tapped into something Biden has not.

While Democrats continue to be haunted by what happened in 2016, there are some notable differences between then and now. Clinton was, in millions of voters’ minds, a highly flawed candidate with a family history and political track record that made many uncomfortable. Some of those voters in key battleground states found Stein, who ran twice on the Green Party ticket and is now advising West, an appealing alternative. There was also a widespread assumption at the time that Clinton would beat Trump and that a third-party vote on principle would not make much of a difference.

Despite their claims to care about “our democracy,” Democrats don’t seem very interested in democracy when it comes to third-party runs.