Vice President Kamala Harris reacted to a report that former President Donald Trump was backing out of interviews because he was “exhausted,” questioning if he was able to “handle the rigors of the campaign trail.”

The report from Politico Playbook said that the Trump campaign had been in talks with The Shade Room, a media company with a website and shows posted on social media that draw an audience that is “largely young and Black,” but “weeks” went by and the show producers felt like the campaign was dragging its feet. Eventually, reported Politico, “a Trump adviser told The Shade Room producers that Trump was ‘exhausted and refusing [some] interviews but that could change’ at any time, according to two people familiar with the conversations.”

The Harris campaign has sought to highlight stories like this to draw a contrast with the 19-year age gap between her and Trump, criticizing him for refusing to participate in another debate and mockingly posting “Hope he’s okay” with a video of Trump’s bizarre behavior at a Pennsylvania event promoted as a town hall but which devolved into 39 minutes of the ex-president dancing on stage to some of his favorite songs. Harris also recently released her medical records and called on her 78-year-old Republican opponent to do the same.

The vice president took some swipes at Trump on these issues Friday at a campaign speech in Grand Rapids, Michigan. “And now he is ducking debates and canceling interviews,” she said. “Come on. And check this out — his own campaign team recently said it is because of exhaustion. Well, if you’re exhausted on the campaign trail, it raises real questions about whether you are fit for the toughest job in the world. Come on!”