The Washington Post Guild, a union, condemned Bezos' decision in a statement on social media, arguing that it was an abdication of responsibility and suggesting that "management interfered with our members in editorial."
Karen Attiah, a Post columnist, called the decision an "an absolute stab in the back," writing on social media.
"What an insult to those of us who have literally put our careers and lives on the line to call out threats to human rights and democracy," she wrote.
Martin "Marty" Baron, a former executive editor at the Post who was lauded for his leadership of the paper from 2012 to 2021, also denounced the decision not to endorse a presidential candidate.
"This is cowardice, with democracy as its casualty. Donald Trump will see this as an invitation to further intimidate owner Jeff Bezos (and others)," he wrote on social media. "Disturbing spinelessness at an institution famed for courage."
The Post has endorsed the Democratic nominee for president in every race since 1976, aside from 1988, when it made no endorsement. The Los Angeles Times didn't issue endorsements for decades but has endorsed the Democrat in each of the past four presidential elections, starting in 2008.
Lewis said the Post would no longer make presidential endorsements and emphasized its commitment to independent, nonpartisan news. He cited editorial board decisions not to endorse in 1960 and 1972, which gave similar rationales.
Lewis was previously the publisher at The Wall Street Journal, which is owned by right-wing billionaire Rupert Murdoch. Lewis' tenure at the Post, which began last year, has been plagued by controversy.
The reasons for Bezos' reported intervention to stop a planned Harris endorsement are not clear, but he has told the paper's leaders that he would like them to seek out more conservative readers and add more conservative opinion columnists, according toThe New York Times.
Some observers have suggested that Bezos, the founder of Amazon, and Soon-Shiong, a biotech mogul, are afraid to antagonize Trump for fear he could retaliate against their businesses when in office.
"The most serious allegation... is that Soon-Shiong and Bezos are trying to hedge their bets out of fear that their business interests could be harmed during a second Trump presidency," Columbia Journalism Review's Sewall Chan, who has worked at both the Post and the Los Angeles Times, wrote on Friday.
"Soon-Shiong, who made his fortune as a biopharmaceutical innovator, is working on new drugs that would presumably require FDA approval," Chan continued. "Amazon faces an antitrust lawsuit, brought last year by the Biden administration, that will take years to litigate or settle."
Robert Kagan, a neoconservative columnist and editor at large at the Post, resigned in protest on Friday, Semaforreported, while suggesting there may be further resignations.
"People are shocked, furious, surprised," an unnamed editorial board member told Semafor about the endorsement decision. "If you don't have the balls to own a newspaper, don't."
Other major newspapers have endorsed Harris, includingThe Philadelphia Inquirer on Friday—with the reminder that "the road to the White House may well run through Pennsylvania and every vote matters." Will Bunch, a columnist at the paper, wrote on social media that "unlike some other news organizations, we will not be silenced, not when everything is on the line for democracy."
The New York Times endorsed Harris on September 30, calling Trump "morally unfit" and "temperamentally unfit" for office.