Former New Jersey Gov. Chris Christie , who was part of Donald Trump s inner circle during his presidency, said the former presidents cognitive skills have been diminishing.

I saw decline in his skills in 20 from 16, Christie told New York Times columnist Frank Bruni . And you see significant declines still.

Christie helped Trump prep for the presidential debates in 2016 and 2020. He said he noticed the changes at the time and has seen him get worse since.

What masks it is that he is still physically pretty vibrant and energetic, unlike the president, Christie said. But if you listen to him and his ability to make a point, its not nearly as good now as it was in 2016, not nearly.

He offered up an example: When then-Fox News host Megyn Kelly confronted Trump during a debate about insults such as fat pig and disgusting animals that he had hurled at women who criticized him, he fired back: Only Rosie ODonnell.

Todays Donald Trump would not have come up with the Rosie ODonnell line in response to what Megyn Kelly did in that first debate, Christie said. He would have yelled at her and cursed at her.

Trump mocked President Joe Biden s mental capacity and even challenged him to take a cognitive test. Since Biden abandoned his reelection bid, however, Trump has been facing those same questions especially after speeches marked by slurred words, confusion over names and location , and long off-topic rambles .

Christie was a Trump rival during the 2016 primaries but dropped out early and became one of the first major Republican figures to endorse him. After Trump left office, Christie turned into a critic and ran against him during the 2024 GOP primaries.

He withdrew from the race before a single primary contest as his campaign gained virtually no traction.

Despite his criticism of Trump, he stopped short of endorsing Vice President Kamala Harris during his new interview with the Times.

Shes got time to convince me, he said. But she hasnt done that yet.

He said he may not vote for anyone for president this time around.

Practically, my vote is not going to matter in New Jersey, anyway, he said. Shes going to win New Jersey by 10 to 14 points.