MORRISTOWN — During a 75-minute lecture at Drew University, U.S. Homeland Security secretary-turned-White House chief of staff John Kelly defended a key witness in the presidential impeachment trial while also touching on several other polarizing issues.

Kelly spoke at the Mayo Performing Arts Center Wednesday night. He defended Lt. Col. Alexander Vindman, who was among administration officials who raised concerns about President Donald Trump’s July phone call with Ukraine President Volodymyr Zelenskiy. That call spurred the president's impeachment trial, which ended in acquittal last week.

“He did exactly what we teach them to do from cradle to grave,” Kelly said at the forum, according to a report by The Atlantic magazine. “He went and told his boss what he just heard.”

Vindman was ousted last week from his position as a Ukraine specialist detailed to the White House National Security Council.

Kelly is a veteran commander of the U.S. Marines, who served briefly as the fifth U.S. Secretary of Homeland Security in 2017. After six months, Kelly was selected to serve as White House Chief of Staff, a position he held until January 2019.

As reported by USA Today, Kelly also said "I'm disappointed in myself for leaving, but it was a killer, I mean, no joke," Kelly said about his time with the Trump Administration.

Trump tweeted about Kelly Thursday morning.

"When I terminated John Kelly, which I couldn’t do fast enough, he knew full well that he was way over his head. Being Chief of Staff just wasn’t for him. He came in with a bang, went out with a whimper, but like so many X’s, he misses the action & just can’t keep his mouth shut."

Among those responding, state Sen. Loretta Weinberg, D-Bergen, responded to Trump: "I guess you know a lot about ax’s."

As reported by the Morristown Daily Record, Kelly also said at the Drew Forum that he thought Trump has been toyed with by North Korean leader Kim Jong Un.

“He will never give his nuclear weapons up,” Kelly said, according to the report, adding, “I never did think Kim would do anything other than play us for a while, and he did that, fairly effectively.”

Trump followed up on Kelly with a second tweet: "His incredible wife, Karen, who I have a lot of respect for, once pulled me aside & said strongly that 'John respects you greatly. When we are no longer here, he will only speak well of you.' Wrong!"

Trump has insisted that his call to Zelenskiy was “perfect.” During the conversation, Trump asked Zelenskiy to do him “a favor” and look into former Vice President Joe Biden and his son’s business dealings in Ukraine.

Vindman testified that he raised his concerns inside the White House after concluding that Trump was inappropriately conditioning nearly $400 million in military aid to the country on getting Zelenskiy's help digging up dirt on the Republican president’s political rival.

Kelly said at the forum that Vindman’s decision to raise his concerns was valid.

“Through the Obama administration up until that phone call, the policy of the U.S. was militarily to support Ukraine in their defensive fight against … the Russians,” Kelly said. “And so, when the president said that continued support would be based on X, that essentially changed. And that’s what that guy (Vindman) was most interested in.”

During the Morristown event, Kelly also said he had a difference of opinion with Trump on the press, as "The media, in my view, and I feel very strongly about this, is not the enemy of the people."

USA Today reported that Kelly continued: "We need a free media. That said, you have to be careful about what you are watching and reading, because the media has taken sides. So if you only watch Fox News, because it's reinforcing what you believe, you are not an informed citizen."

Trump suggested earlier this week that the Pentagon should review Vindman’s conduct in the Ukraine episode and potentially consider disciplinary action against him.

Vindman was ousted from his job on the White House National Security Council last Friday, just two days after the Senate acquitted Trump on abuse of power and obstruction of justice charges. He is to be reassigned by the Pentagon.

His twin brother, Lt. Col. Yevgeny Vindman, who worked as an ethics lawyer at the NSC, also was ousted from his job and was re-assigned to the Army General Counsel’s Office.

Kelly said at the Drew Forum he had some hesitation about joining the Trump Administration but ultimately decided to, at the urging of his wife.

Outside the venue, some theology graduate students from Drew University organized a protest of Kelly's appearance, over what they called "Kelly's abhorrent actions" during his support of migrant family separation at the U.S. border as well as what amounted to a "Muslim ban" on travelers.

The graduate students previously said they were "called to action" because of their faith.

The Morristown Daily Record also said that protesters also interrupted the event twice inside, shouting about how "separating families is inhumane."

Kelly said during his lecture that the vast majority of people crossing into the U.S. "are good people," while adding: "The fact, is, though, is they are crossing illegally."

There was no mention Wednesday of Kelly's current position, with the parent company of the country's largest shelter for unaccompanied migrant children, as reported by CBS News.

The Associated Press contributed to this report. 

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