Christie prosecuted Kushner's father, Charles Kushner, in 2004 when he was USA attorney for New Jersey and claims that was the reason the younger Kushner got him fired from heading Donald Trump's transition team after the 2016 election.
But soon after Trump was elected, Christie joined his team and became a leader during the transition-a role that many expected to turn into an administration position.
The pair then continued the conversation about Christie's current constituency with Colbert pointing out his current 15 percent approval rating in New Jersey.
Christie has been out of the inside Trump orbit for a while, and he's now making the rounds as he pushes a new book titled "Let Me Finish: Trump, the Kushners, Bannon, New Jersey, and the Power of In-Your-Face Politics". "So you might be even more sad than you are now", he said.
"Once you've got this in your blood, it's hard to get rid of", Christie said.
"And that's why I made the decision".
On Friday, Trump agreed to a three-week spending package that allowed the government to reopen after the longest shutdown in American history - a shutdown that Christie didn't think was well-thought-out.
"That great political philosopher, Cardi B", Christie said with a laugh.
Christie wrote that Kushner joined in to back Trump's side, saying, "That's right, firing Flynn ends the whole Russian Federation thing".
"I want to say this in the nicest possible way", Colbert began. If you're convicting murderers, it's one thing. I just never wanted to be on the other side of that and cause pain to the families I was doing that to, whether right or wrong. "And so if it doesn't go well in the first couple of days, you gotta have a way to get it back open".
"Yeah, I do, absolutely", Christie said.
While Jared has yet to comment on the claims, the former adviser to Trump also alleged that ex-White House chief Strategist Steve Bannon had told him that Kushner "got me fired from that job".