Tucker Carlson said Representative Ilhan Omar “hates this country” during his Fox News program Tuesday night. The Minnesota Democrat responded by saying that the Fox News host is “a racist fool.” And so begins another contretemps in a news cycle dominated by President Donald Trump.

During his 8 p.m. hour Wednesday on Fox News Channel, the opinion host offered remarks suggesting that Omar, a Somali-born woman who arrived in the United States as a teenager, should stop criticizing elements of U.S. policy. “After everything that America has done for Omar, and for her family, she hates this country more than ever,” Carlson said. He also suggested to viewers that “maybe we are importing people from places who are simply antithetical to ours.”

Carlson also offered comments supportive of immigrants and Omar’s rise to Congress. “Some of our deepest satisfaction as a country comes from watching penniless immigrants arrive on our shores, buy into our values and thrive.  We call it the American dream and nothing makes us prouder,” he said, adding later: “Omar is now at the age of only 36, one of the most powerful women in America. It’s an amazing story really. Only in this country could it have happened.”

Carlson has come under scrutiny a handful of times in recent months for remarks about immigration. In December, some advertisers in his program, “Tucker Carlson Tonight,” indicated they would suspend their appearances in his program. Fox News has said it has moved advertisers elsewhere in its schedule when necessary, but has not seen any decline in overall ad revenue.

Omar railed against some of Carlson’s comments via Twitter both Tuesday night and Wednesday. “Not gonna lie, it’s kinda fun watching a racist fool like this weeping about my presence in Congress,” she tweeted, adding that “no lies will stamp out my love for this country or my resolve to make our union more perfect. They will just have to get used to calling me Congresswoman!” She was responding to a clip of Carlson’s remarks posted on the social-media venue by a staffer from Media Matters, a progressive advocacy group that routinely opposes Fox News and works to get advertisers to boycott its programs.

On Wednesday afternoon, Omar took to Twitter to suggest advertisers consider similar moves. “Fox News is now giving a nightly platform to white supremacist rhetoric. It’s dangerous,” she said. “Advertisers should not be underwriting hate speech.”

Carlson plans to address Omar’s comments on Wednesday’s broadcast of his Fox News program. “Anyone who values democracy and free expression should be gravely concerned when members of congress demand that their critics be silenced,” said Justin Wells, senior executive producer of Fox News’ “Tucker Carlson Tonight,” in a statement.  “Tucker will address this on tonight’s show.”