Jimmy Kimmel presented his 10th edition of Celebrities Read Mean Tweets on his show Wednesday night. Unfortunately, his guest Bill O’Reilly did not participate.

The Fox News host was on Jimmy Kimmel Live to promote the latest in his “Killing” book series, this one covering “How America Vanquished World War II Japan,” but of course what Kimmel really wanted to talk about—and what viewers really wanted to hear about—was Donald Trump.

Aside from the occasional sit-down with hard-hitting journalists like Matt Lauer, Dr. Oz, and Jimmy Fallon, Trump has been sticking to Fox News more and more as the election approaches, preferring to answer friendly inquiries from supporters like Sean Hannity. While O’Reilly is hardly holding Trump’s feet to the fire, he might be the candidate’s toughest regular interviewer these days.

“When I watch you speak to Donald Trump, I don’t think you go easy on him at all,” Kimmel told his guest. “And in fact, I’d even say that sometimes I feel like when you’re interviewing him, that maybe you’re not actually going to vote for him.”

O’Reilly wouldn’t say whether he would vote for Trump, saying he “never” reveals his own voting preference. “I never endorse anybody,” he said. “If I endorse someone, they will be arrested the next day, all right? That’s going to happen. It’s just my karma.”

After playing a clip of O’Reilly failing to challenge Trump on the question of racial profiling earlier this week, Kimmel asked, “Isn’t that un-American, to suggest that we should be racially profiling Americans?” The Fox News host said, “no,” adding, “You have to give the law enforcement a little bit more room here, you have to tell the American people, ‘Look, it isn’t personal, we just need to get as much security in place as possible.”

Later, O’Reilly told Kimmel he has “no idea” whether Trump will do well in the first presidential debate next Monday, but then proceeded to give his analysis anyway. “Trump could say anything at any time,” he said. “Trump won the Republican debates by saying stuff like, ‘You’re boring. you’re fat, you’re sweating.’ That’s how Trump won.” He added, “I thought I was watching Don Rickles.” If Trump does the same with Hillary Clinton, calling her “crooked” right out of the gate, O’Reilly said Trump will “lose.”

O’Reilly then launched into a false equivalence about Clinton, saying she’s calling Trump “all sorts of names,” such as misogynist and racist. “If she starts that, she’ll lose,” he said. “Because Americans want problem solving. We’ve heard the insults, you don’t need any more of them. It’s the best case, and both have to make their case.”

While Trump is not a “policy guy,” O’Reilly said Clinton would be smart to get into policy as quickly as possible on Monday night. “And then look at him and go, ‘Do you know what I’m talking about?’ Because maybe he won’t.”