"You can take out my ankles, you can take out my knees, but I'm still going to stand up for Barack Obama," Booker, 43, told the crowd Tuesday, just hours before he presented the party platform on the floor of the Democratic convention.
As Florida delegate Juanita M. Scott waited backstage to meet Booker afterward, she was asked if she had heard his speech.
"Did I hear him? I wanted to jump into his body and be him," she said, declaring it the best introduction to a politician she had heard since Barack Obama delivered the Democrats' keynote in 2004. "He was flipping awesome."
That reaction is just one reason insiders from both parties say that if Booker chose to take on Gov. Christie next year ("likely not," Booker said in an interview), he would immediately clear the field of other potential Democratic challengers.
But it's not just because of the oratorical skills. Or the 1.2 million Twitter followers who were swiftly treated - or rather, tweeted - with a gory picture Tuesday of Booker's inflamed ankle. Or the biography that includes compiling degrees from Yale, Oxford, and Stanford before choosing to move into a notorious Newark public-housing project.
What really has Democrats from around the country buzzing about a possible gubernatorial challenge - or even something higher than that - is Booker's propensity for heroics, from the sprained-ankle speech to his lifesaving rescue of a neighbor in April from a burning building.
The reason is that a hero is exactly what Democrats may need to beat Christie, whose popularity in the Garden State is hovering around 50 percent and who can raise more money than just about any incumbent in the land.
But there's a catch: Booker has supported Christie for the most significant accomplishments of the governor's term, from a 2 percent cap on tax increases to the reorganization of the state's higher-education system. Their education positions are identical; together, they appeared on Oprah to accept a $100 million pledge for Newark schools from Facebook founder Mark Zuckerberg.
And Booker doesn't publicly attack Christie - rare for state Democrats. Even rarer for Christie, the governor doesn't criticize Booker. They call each other friends.
In the Tuesday interview, conducted in Booker's SUV after he'd headlined a Planned Parenthood rally (where anti-Mitt Romney condoms were distributed), Booker dismissed chatter about his political future, saying it is inappropriate to "bring 2013 into 2012."
"We are not in a political season in New Jersey right now. This is not the time," he said, "to stake out differences and foist political attacks."
Booker held up his friendship with Christie as an example. "We could have spent the last three years attacking each other, and it could have been very easy," he said. Instead, they met when Christie was governor-elect and decided to pursue compromise instead of warfare.
"What I get tired of in the United States of America right now is partisanship for partisanship's sake," said the second-term mayor. "I'm trying my best to be the change I want to see in American politics."
Yet if he wanted to, he said, "I could sit down and write a dissertation on disagreements" with Christie. He noted a few: tax policy, the environment, same-sex marriage.
But he said he has run against friends before - three of them, actually, for student government in seventh grade. (Booker won.)
Christie is "more pugilistic" than he, Booker said. But they are remarkably similar politicians. Both are criticized by foes for building national reputations while forsaking their day jobs. (Booker reportedly gets as much as $40,000 per speech.) Both are prone to self-promotion via social media, tweeting pictures of themselves preparing for their speeches at their respective conventions.
Booker defended his national prominence, saying it has been estimated that each of his trips out of state brings back $500,000 in philanthropy from the deep-pocketed people he hobnobs with. In all, $300 million in donations has helped pay for salaries of policy advisers and bulletproof vests for Newark police.
His trips have also attracted developers to the city, which is undergoing the most economic development it has seen since the 1950s, he said. "Even on this trip here," he said in Charlotte, "I'm collecting business cards."
For example: Vice President Biden invited him to his convention luxury box Tuesday night. "I'm very excited to see the vice president," Booker said, "but I want to see who else is in that box and how they're going to help Newark."
Relations between the Obama team and Booker seem to have warmed since May, when, in a TV interview, he called Democratic attacks on private equity "nauseating."
Booker issued an online video to try to clarify his remarks, and he has since been a strenuous surrogate for the president.
At the Florida breakfast, using the "four years ago" refrain, Booker at one point spoke over sustained applause to tout Obama's record.
"Don't you dare tell me America is worse off than it used to be," he said. "I know the truth, and the truth will set you free!"
As sweat poured down his bald head, a woman in the audience approached the lectern to hand him a napkin.
"Jesus loves you, and so do I," he said to her. He then dropped the Hebrew for "God Bless," Baruch Hashem.
"I'm getting everything out of Florida. Y'all think you can help me find my beshert, too?" the single mayor asked, using the Yiddish word for soul mate.
The Floridians loved it.
Hours later, he received the first standing ovation of the convention as he walked on stage just before 6 p.m. to deliver the Democratic platform for the next four years.
"Our platform is crafted by Democrats, but it's not about partisanship, it's about pragmatism," he said. "It's not about left or right, it's about moving America and our economy forward."
His speech, which touched on equality, education, and infrastructure investment, ended with "Cory" chants from the arena.
He then walked off stage, with no sign of a limp from the bum ankle.
Contact Matt Katz
at 609-217-8355 or email@example.com, or follow on Twitter @mattkatz00. Read his blog, "Christie Chronicles," at www.philly.com/christiechronicles