Newsweek has apologized for an op-ed published on Wednesday that questioned Kamala Harris’ eligibility as Joe Biden’s pick for vice president. An editor’s note added to the article on Friday apologized and said the original piece was “being used by some as a tool to perpetuate racism and xenophobia.”

The op-ed was written by conservative law professor John C. Eastman and titled “Some Questions for Kamala Harris About Eligibility.” In it, he falsely argues that Harris, whose parents emigrated from Jamaica and India, “may not be subject to the complete jurisdiction,” even though she was born in California, making her a U.S. citizen under the Fourteenth Amendment.

Newsweek was hit with criticism for publishing the essay after many people online compared it to the birther conspiracy theory that falsely suggested President Barack Obama was not eligible to hold office.

“The op-ed was never intended to spark or to take part in the racist lie of Birtherism, the conspiracy theory aimed at delegitimizing Barack Obama, but we should have recognized the potential, even probability, that that could happen. Readers hold us accountable for all that we publish, as they should; we hold ourselves accountable, too. We entirely failed to anticipate the ways in which the essay would be interpreted, distorted and weaponized,” said the editor’s note written by opinion editor Josh Hammer and global editor-in-chief Nancy Cooper.

The birther conspiracy was largely peddled by conservatives, including most prominently by President Trump. Last week, Trump told reporters that he’d heard somewhere that Harris was ineligible to be chosen as vice present, giving some credence to the false conspiracy.

“I heard it today that she doesn’t meet the requirements,” he said. “I have no idea if that’s right. I would have thought, I would have assumed that the Democrats would have checked that out before she gets chosen to run for vice president.”