Failed presidential candidate Hillary Clinton joined James Corden on Tuesday’s edition of the Late Late Show to mock President Donald Trump, fuelling speculation that she may be preparing a 2020 presidential run.

Hillary Clinton made a surprise appearance alongside her daughter Chelsea during Corden’s monologue, with the pair receiving a prolonged standing ovation from the audience.

“I’m really fed up with all your Trump jokes. Every single night,” Hillary joked. “If anyone should be telling Trump jokes … it’s me.”

With that, Corden stepped aside and gave the two women a chance to take shots at Trump and his former press secretary Sean Spicer, who has received support from Trump as he continues to compete and win on the dance competition show Dancing on the Stars.

“I can’t blame Trump for trying to help Sean Spicer,” Hillary explained. “But if it’s one thing we’ve learned, it’s that these guys really can’t win the popular vote.”

After their monologues, the ladies sat down for an interview with Corden, who asked Hillary what her advice would be to the 2020 Democratic candidates that may end up debating and facing President Trump in the general election.

“Just be really prepared,” Hillary said of the debates. “As hard as it is with him to try and talk about facts and truth compared to what he says, be prepared anyway to try to make your case and just keep going at him and don’t give him an inch.”

The 72-year-old also revealed she was surprised by Rudy Giuliani’s recent work with Trump as his personal attorney, with the pair having worked together when Guiliani was the mayor of New York City and Clinton was a junior U.S. senator.

“I mean, he was a tough guy, he was a mayor, he was mayor during 9/11, I was a senator, I worked with him,” she said. “I don’t know what happened. It’s almost like aliens have seized his brain. Truly he’s been possessed.”

Accusing Guiliani of saying things that are “demonstrably untrue,” Hillary Clinton added that she doesn’t “understand when it happened, but it is a very clear case of a man who has gone over the edge, probably pushed.”

Clinton’s appearances on late-night comedy shows fuels speculation that she may be preparing a run in 2020. As reported by both the New York Times and Washington Post last month, Clinton has yet to rule out running against Donald Trump, while establishment Democrats remain concerned that none of the current candidates could defeat him in next year’s presidential election.

The launching of a third presidential bid would be highly unusual given how most candidates have already launched their campaigns and participated in televised debates. However, Clinton’s refusal to rule out the possibility remains intriguing, with a source close to her recently telling the Post that although it remains “unlikely” to happen, there is still a possibility.

“But put it this way: It ain’t zero,” said the source. “And does she think about it all the time? Absolutely.”

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