"I wanted to scream out, Obama, say, 'keep your accountant, they're allowing you to pay only 13 percent in taxes,' " Booker said. "The rest of us should have accountants like that."
But, Booker conceded, the "right advice" for Obama was to "stay presidential."
"That's like a shot I don't want to hear from my president," Booker said. "So he's got a fine line to walk. The reality is, I would have liked to see some hard punches to the gut when Romney would say something factually inaccurate, like President Obama was raiding ... from Medicare, which is factually inaccurate."
"I have no idea what you’re talking about. I maybe need to get a new accountant," Romney replied. "The idea that you get a break for shipping jobs overseas is simply not the case."
Booker also said that he found Vice President Biden's "off-script" moments to be "refreshing" as he previewed the upcoming debate between Biden and Romney running mate Rep. Paul Ryan (R-Wis.).
"I think the American public are going to see a guy who's really passionate and gets very excited about the dramatic differences. Now, that means that sometimes people accuse him of going off-script or whatever," Booker said during an appearance on CNN's "Starting Point." "But that's refreshing to me. I really crave, from both sides."
Booker went on to say that a similar off-the-cuff style was why he liked Sen. John McCain (R-Ariz.) during his first run for president.
"It was a rawness, it was a truth, shooting from the hip, as opposed to the guy who had to run hard to the right, like many Republicans have to do to get their primary wins and the like," Booker said. "What we need tonight is just a pure, unadulterated honesty from both sides."
The Newark mayor also said he hoped that Ryan would be willing to engage more openly on his House Budget proposal and legislative history during Thursday's debate, some evidence that the Obama campaign is hoping to engage with the Wisconsin lawmaker on his proposals.
"Tell people the truth of really what you want to do to Medicare and Social Security, the kind of stuff you said until you were a candidate, and now you're trying to shift to the middle for votes," Ryan said. "I want to hear the raw truth, because Americans are definitely going to have a real choice."
Booker went on to say that the debate had real significance on the race, and quip that if the contest "were on Pay-Per-View, I would pay to watch this."