Sarah Matthews, a onetime spokesperson to former President Trump, said Monday the GOP presidential nominee is embracing false theories about his political opponent because he’s getting “desperate” as Vice President Harris’s campaign benefits from a boost in voter enthusiasm.

“I think that he feels this election slipping away from him, and that’s where you’re beginning to see him spiral and cling to these conspiracy theories, as you noted with the AI-generated crowds, which obviously can be easily disproven,” Matthews said in an interview on MSNBC’s “Inside with Jen Psaki.”

Trump and Republicans have appeared to struggle to find a cohesive message against Harris as she sees gains in the polls and rides the momentum of her young campaign.

Trump has dismissed the large, enthusiastic crowds Harris has drawn at rallies, even embracing false online theories that the crowds seen in photos and videos are generated by artificial intelligence (AI) technology.

“I know it’s insanity,” Matthews said. “There will be people out there that will believe it, though, because he’s pushing it. And that’s what happens when he gets desperate, is he pushes these conspiracy theories.”

Matthews cited other recent examples where Trump has embraced messages that she said seem to bring more harm than good to his campaign, including his recent interview at the National Association of Black Journalists convention, where he questioned Harris’s racial identity as a Black woman, saying she “happened to turn Black.”

Matthews also pointed to Trump’s recent rally in Georgia, where he attacked the state’s popular Republican governor, Brian Kemp, who refused Trump’s efforts in 2020 to help the then-president “find” votes in his state to reverse the results of the 2020 election in Trump’s favor.

“These are not winning campaign messages,” Matthews said. “But that is what he does when he feels like he’s under attack, is he uses these kinds of lines of defense that don’t make much sense for campaigning.”

The Hill has reached out to the Trump campaign for a response.