Gov. Tim Walz delivered remarks at a rally in Wilmington, North Carolina, on Thursday centered around an assertion that former President Donald Trump is dangerous and unfit for the Oval Office on the heels of Trump White House Chief of Staff John Kelly's recent remarks about his former boss.

"The people who know Trump best, who sat beside him in the Oval Office, who were in the Situation Room, are now finding the courage to come out of the woodwork and sound the alarm. As I said, Vice President Harris called it a '911 to the American people,' because these insiders know that Donald Trump of 2016 is not the Donald Trump of 2024," Walz warned.

Walz reiterated that there will be no guardrails in a second Trump term and that he’d be given virtually unchecked power by the Supreme Court, which could even become more conservative.

“When he says he wants to be a dictator on day one of his presidency, he's not just saying it, he's promising it. I've been saying it, and I think you feel it. You've seen it over the last few weeks. Hell, we've seen it over the last nine years, but certainly the last few weeks. This is a straight-up descent into madness in front of us, and he's repeatedly talking about it," Walz said.

Former President Barack Obama took the stage in Atlanta following a performance from Bruce Springsteen and speeches from Tyler Perry and Sen. Raphael Warnock repeating his message to get Georgians to vote.

Obama wasted no time bashing former President Donald Trump over his policies and rhetoric.

"We know this election is going to be tight because a lot of Americans are still struggling," he said. "What I cannot understand ... why anybody would think that Donald Trump would be able to shake things up for you."

Obama ripped into Trump for his rambling speeches, peddling of products such as shoes and bibles, stating "All he cares about is his ego."

"Just because he acts goofy doesn't mean his presidency wouldn't be dangerous," he warned.

Obama brought up the recent comments by Trump's former Chief of Staff John Kelly and Trump's claims to go after the "enemy within."

"Unlike the first time, he won't have people like John Kelly around to stop him. He'll have people who are just as looney as he is, and let him do what he wants" he said.

Obama touted Vice President Kamala Harris as the candidate who listens to the people and "is ready for the job."

"If you elect Kamala Harris, she will not be focused on her problems, her ego, her money. She's going to be focused on you," he said.

Bruce Springsteen kicked off the first of two appearances at Harris rallies on Thursday night.

The Boss performed "The Promised Land," "Dancing in the Dark" and other hits before the other VIPs, including President Barack Obama, took the stage.

The crowd chanted "USA!" and "Bruce!" as he performed.

Trump continued to lash out Thursday at former John Kelly, his former chief of staff and a retired Marine Corps general, over his his claims that Trump was a fascist and had an affinity for Adolph Hitler's generals.

While he bashed Kelly with childish insults, Trump didn't respond directly to Harris calling him a fascist despite being given an explicit chance to do so during a call in interview with WABC's Cats&Cosby radio show.

“John Kelly was a stupid person," Trump said. "He had two things. He was tough, but ultimately became a marshmallow. At the end of his time, I fired him, he sat in his office and he was as weak as anybody I've ever seen."

Trump then attacked several high-profile military leaders who have denounced the former president, including former Secretary of Defense Mark Esper and retired generals Mark Milley and Jim Mattis.

Later, Trump continued his defamatory rhetoric toward special counsel Jack Smith. As he discussed immigration, alluding to his plan of mass deportations on his first day in office if he's elected, Trump suggested that he should deport Jack Smith, too.

"Jack Smith should be considered mentally deranged, and he should be thrown out of the country," Trump said.
Trump's running mate, Sen. JD Vance, echoed the former president's comments at a rally at Waterford, Michigan, calling Kelly a "disgruntled ex-employee."

Vance questioned Kelly's truthfulness claiming that other Trump staffers had refuted his claims.

"Do we believe multiple eyewitnesses, or do we believe a disgruntled ex-employee?" he asked.

-ABC News' Kelsey Walsh, Lalee Ibssa and Soo Rin Kim