Chris Christie was booed on stage while speaking at the Faith and Freedom Coalition on June 23, causing frustration from attendees who were unwelcoming to his negative comments on Trump.

The former governor of New Jersey centered his speech on Trump's "character," stating that he "let us down" by failing to accept responsibility for his errors.

“He’s let us down because he’s unwilling to take responsibility for any of the mistakes that were made, any of the faults that he has, and any of the things that he’s done,” Christie said.

“And that is not leadership, everybody; that is a failure of leadership.”

The Response

Some in the audience shouted him as he spoke, but he maintained his opinion of Trump. Others in the audience applauded his remarks.

“You can boo all you want, but here’s the thing: Our faith teaches us that people have to take responsibility for what they do.

"People have to stand up and take accountability for what they do,” Christie said, earning more cheers than he received boos.

Christie went on to criticize Trump for using smear tactics against the former governor, “even after he offered me White House chief of staff,” Christie said.

“I will tell you, if all you do, all you do is disagree with someone, and in return, you get that kind of treatment … doing those kinds of things makes our country smaller,” Christie said. “It makes our country smaller, and it makes us lesser.”

Christie's History of Criticizing Trump

Christie immediately began attacking Trump after announcing his campaign, calling the former president "self-centered" on June 6. Christie, a former federal prosecutor, was one of several potential 2016 Republican presidential contenders, including Trump.

Current opponents of Trump's have started criticizing him as soon as he announced his third attempt for the presidency.

After launching his campaign with a town hall at Saint Anselm College, Christie made it clear that he had no qualms about directly challenging Trump or even using his name repeatedly when campaigning.

“A lonely, self-consumed, self-serving mirror hog is not a leader,” Christie said.

“The person I am talking about, who is obsessed with the mirror, who never admits a mistake, who never admits a fault, who always finds someone else and something else to blame for whatever goes wrong—but finds every reason to take credit for anything that goes right—is Donald Trump.”

Recent polling data showed Trump with 59 percent support in a potential Republican primary, and Florida Gov. Ron DeSantis holding onto 21 percent. Christie polled just 2.4 percent.