Geraldo Rivera was deeply unimpressed with Kamala Harris’ performance during her interview on Fox News Wednesday, arguing that she seemed unprepared for inevitable questions about immigration.

Rivera, a former Fox News host who said this week that he intends to vote for Harris next month, said on NewsNation after the interview aired that he thought Harris had been “tougher than she has been, feisty, more mature and confident” during her interview with Bret Baier. “But I still am baffled by the lack of preparation going into a high profile—the highest profile interview—she has,” Rivera added.

He said that Harris’ team should have been aware that the vice president was likely to face a grilling “all about immigration.”

“Bret was gonna come out smoking on immigration,” Rivera said. “And he would culminate his lament over awful the situation is with pictures of the victims. I mean, that’s the Republican playbook—it was obvious that it was coming. How could she not be ready to answer Laken Riley and Mollie Tibbetts and so forth?”

Rivera then proceeded to read comments from Riley’s father, Jason Riley, in which he spoke about how the exploitation of his daughter’s death for political purposes made him angry. The 22-year-old nursing student’s killing in Georgia in February became a flashpoint in the national debate around immigration when Jose Ibarra, a man from Venezuela who entered the U.S. illegally, was accused. He has pleaded not guilty to multiple charges.

“Why couldn’t the vice president say … as she did that these are tragic deaths and the hearts go out and punched in the gut by it, but also say that these people, these poor victims, are being used for political purposes?” Rivera asked. “To me that’s politics 101.”

He added that he’s not a politician but he knows “a thing or two about debates.”

“It just seems to me that she missed an opportunity, her briefers did, and from this moment on I advise them to not be the doormat when it comes to this issue,” Rivera said. “It is their biggest Achilles heel, there’s no doubt about it. If Donald Trump wins it will be largely because of the immigration issue and the fact that Democrats not only blew the reality on the border over the last three-plus years, but they don’t know how to respond to it, I think is malpractice.”

Rivera’s criticisms come after he announced Monday that he would not be voting for Trump—someone he once considered a “loyal friend”—in the election, citing the Republicans lies that the 2020 election was stolen.

“Former President Trump is a sore loser who cannot be trusted to honor the Constitution,” Rivera wrote in a post on X. “That is why I am voting for Kamala Harris to be our 47th President.”