Former San Francisco 49ers quarterback Colin Kaepernick and the White House press machine are the latest to speak out after ESPN anchor Jemele Hill called Donald Trump a “white supremacist”.

Hill made her statement in a series of replies to her followers on Twitter. “Donald Trump is a white supremacist who has largely surrounded himself [with] other white supremacists,” she wrote.

“The height of white privilege is being able to ignore his white supremacy, because it’s of no threat to you. Well, it’s a threat to me,” she added. “... He is unqualified and unfit to be president. He is not a leader. And if he were not white, he never would have been elected.”

Donald Trump is a white supremacist who has largely surrounded himself w/ other white supremacists. — Jemele Hill (@jemelehill) September 11, 2017

On Wednesday, the White House condemned Hill’s comments. “That is one of the more outrageous comments that anyone could make and certainly is something that is a fireable offence by ESPN,” said White House spokeswoman Sarah Huckabee Sanders. “I’m not going to speak for that individual but I know that the president has met again with people like Senator Scott who are highly respected leaders in the African American community. He’s committed to working with them to bring the country together. I think that’s where we need to be focused; not on outrageous statements like that one.”

Hill’s attack on the president caused ESPN to issue an apology on Tuesday, with the broadcaster saying her views “do not represent the position of ESPN.” And “she recognizes her actions were inappropriate”.

On Tuesday night, Kaepernick sent a tweet addressed to Hill, saying “we are with you”. Kaepernick is currently without an NFL team, something that is widely seen as due to his protest against racial injustice in the US. As part of the protest, Kaepernick chose not to stand during the national anthem last season.

ESPN has long faced attacks from figures on the right, who accuse the broadcaster of liberal bias. In a blog earlier this year, Fox Sports’ Clay Travis attacked ESPN because it has “given awards to Caitlyn Jenner for becoming a woman, celebrated Michael Sam’s bravery in coming out gay like he was a modern-day Jackie Robinson, and covered Colin Kaepernick like he’s a modern-day Rosa Parks.”

Hill, who is black, received significant amounts of racist abuse from Twitter users following her comments. She has been with ESPN since 2006. In February this year she was appointed co-host of the broadcaster’s flagship 6pm edition of SportsCenter alongside Michael Smith.

Last month Hill discussed politics and Twitter with Sports Illustrated. “I don’t tweet a lot about politics,” she said. “I do tweet more about social issues, which I consider to be issues of morality. Racism isn’t politics. Racism is an issue of right and wrong.”