Bernie Sanders pulled his support for Cenk Uygur’s congressional bid, with the Vermont independent in part acknowledging that Sanders’ supporters were “frustrated” about the endorsement.

Sanders, who’s running for the 2020 Democratic presidential nomination, cited Uygur’s announcement Friday that he would not be accepting any endorsements. In a statement, Sanders alluded to sexist and other controversial comments Uygur has made in the past but did not directly address them.

Since Uygur, founder of liberal-leaning Young Turks internet news and opinion network, launched his congressional campaign last month, at least a dozen women’s, LGBTQ and Democratic organizations have denounced past comments and segments by the online talk-show host as sexist, racist, homophobic, anti-Islam and anti-Semitic.

In a tweet Friday, Sanders wrote, “.@cenkuygur has been a longtime fighter against corruption. However, our movement is bigger than any one person. I hear my supporters who were frustrated and understand their concerns. Cenk today said he is rejecting all endorsements for his campaign and I retract my endorsement.”

Also Friday, Rep. Ro Khanna (D-Calif.) rescinded his endorsement of Uygur, saying that Uygur’s “statements were wrong and hurtful which he has acknowledged.”

Uygur’s sexist and racist commentary has included a segment from his Young Turks show in 2013 in which he ranked women on a scale of 1-10 on “how likely men would be to let them perform oral sex on them,” per the L.A. Times. That same year, Uygur called a model “obviously anorexic” on the show and said she looked “like she’d just come out of a [concentration] camp.” In 2015, Uygur hosted ex-Ku Klux Klan leader and neo-Nazi David Duke on the Young Turks in an anti-Semitic segment about “how Jews control everything.” Video also has surfaced of Uygur using the n-word repeatedly on TYT in 2007. Last year, Uygur’s TYT Network was sued by an ex-employee alleging racial discrimination; Uygur has called the complaint “baseless.”

Uygur said he deleted older posts disparaging women, telling CNN’s Chris Cuomo in a Dec. 3 interview, “This is not me. I was trying to be a stupid, politically incorrect Republican. So I wrote these things that I knew were offensive.” Uygur also insisted the Young Turks name has “absolutely nothing to do” with the Armenian genocide; he said he disavowed an editorial he wrote while in college claiming there was no evidence of the Ottoman Empire’s perpetration of the Armenian genocide in the early part of the 20th century.

Uygur is campaigning in a special election to fill the U.S. House of Representatives seat in California’s 25th congressional district that was vacated with the resignation of Katie Hill in late October. Uygur currently does not live in the district but has claimed he plans to relocate to the area.

On Thursday, Sanders had announced his endorsement of Uygur, citing his “strong support” for the Medicare for All program and saying Uygur was “a voice that we desperately need in Congress and will be a great representative for CA-25 and the country.”

Uygur’s opponent in the special election is California Assemblywoman Christy Smith, who has the backing of several prominent Democrats in the state including House Speaker Nancy Pelosi, California Gov. Gavin Newsom, and Sens. Dianne Feinstein and Kamala Harris. A primary in the special election for the seat will be held March 3, 2020.

In announcing plans to run for the congressional seat Nov. 14, Uygur said he entered the race to fight “bribes from corporate interests and lobbyists” that represent a “greedy, corrupt donor class.”

The 49-year-old Uygur founded The Young Turks in 2002 as an online-radio show, and the company has since grown to encompass multiple shows and claims to generate over 200 million views a month. TYT Network two years ago raised $20 million in funding from investors including Jeffrey Katzenberg’s WndrCo media investment firm.