Former New York City Mayor Rudy Giuliani (R) on Sunday defended New Jersey Gov. Chris Christie (R), saying it’s “pretty darn credible” that Christie did not know about a decision to close lanes of the George Washington Bridge last September that resulted in gridlock in Fort Lee.

Giuliani said on ABC’s “This Week” that “you miss a lot of things” during campaign mode.

“Every administration, every president, every mayor, every governor, something goes wrong below them and then the press ask, 'gosh, how do they not know? How did they not realize?,' ” Giuliani said.

“The reality is, he says he didn't realize. He says he didn't know. I think it's pretty darn credible. He wouldn't make this blanket denial unless it's not true.”

“This is what happens in political operations,” Giuliani added. “The people in the IRS thought President Obama wanted them to do this. President Obama didn't want them to do this. But they got the sense because of that culture that they were supposed to target right wing groups. It was totally wrong.

“I think it was totally wrong for these people to have interpreted Chris Christie this way.”

Giuliani, however, said Christie’s political career is at “risk” if evidence surfaces showing he hasn’t been truthful.

“Look, he's handled it the best way you can possibly handle it. He's held a press conference, he's flatly denied it. If for some reason it's not true, the man has put his political career completely at risk. If it turns out that there's some evidence that he knew about it, he's taken the complete risk that his political career is over,” Giuliani said.

“I don't think he would do that if there's any suggestion he knew about this.”