If anyone wonders if two-term Newark Mayor Cory Booker is really committed to campaigning for the Senate from New Jersey, he left no doubt on Monday night at a fancy dinner with fancy New Yorkers.

“Yes!” he told CBS This Morning anchor Norah O’Donnell during a mealtime Q&A presented by The Atlantic magazine and the Aspen Institute at the trendy Del Posto restaurant in Manhattan’s Chelsea neighborhood. “Unofficially, I’m running.”

In the 35-minute chat, O’Donnell managed to pose a few questions while Booker displayed his ability to speak in lengthy, well-ordered paragraphs—a gift that could come in handy during a Senate filibuster.

The African-American Democrat, who was first elected in 2006 to oust the corrupt administration of Sharpe James (a former federal prison inmate), praised the power of Twitter, a platform he uses fanatically to communicate with constituents and the wider world of nearly 1.4 million followers, regaled his audience with a story of engaging talk-show host comic Conan O'Brien in a fake feud over an ungenerous joke about Newark, defended his record on crime and schools, and argued for his “pragmatic, bipartisan” brand of politics that lets him work closely with Republican Gov. Chris Christie on economic development and public education issues.

Although Booker has campaigned for the popular governor’s Democratic opponent, state Sen. Barbara Buono, he effusively praised Christie’s tough negotiating stance with New Jersey’s public employee unions and their “crazy rules” that didn’t require employees to make contributions to their health insurance premiums.

“Jon Corzine didn’t change those rules,” Booker said, criticizing Christie’s Democratic predecessor.

And even though Booker describes himself as a staunch supporter of same-sex marriage, he pointed out that he didn’t raise the issue during an hourlong meeting with Christie in February 2012, as the governor vetoed a bill to legalize the practice. Booker said that instead of wasting energy on a fruitless effort to change Christie’s mind, he preferred to spend his time lobbying the governor on economic development for Newark.

He said his practical approach would allow him, in the United States Senate, to find points of agreement even with hardline conservatives like Rand Paul of Kentucky and Ted Cruz of Texas.

“I can make partnerships across the aisle and get things done,” Booker said, adding that, like Paul, he believes that harsh criminal sentences for nonviolent illegal drug violations have been a “colossal failure.” “I can work with Rand Paul. I can work with Ted Cruz. I love libertarians.”

Recent statewide polls indicate that the 44-year-old Booker, who has filed the necessary papers but has yet to formally declare, is the prohibitive favorite to replace ailing and retiring Lautenberg, 89, who initially took umbrage at the mayor’s in-your-face ambition, suggesting that Booker was being “disrespectful” and needed a “spanking” for openly considering a Senate run before the incumbent had announced his own plans.

Booker’s knack for attracting favorable media attention—personally chasing down muggers, shoveling out snowbound driveways, rushing into burning buildings to save residents, inviting Hurricane Sandy victims to live in his house, and hanging out with Oprah—has made him a national celebrity, surely the country’s most famous mayor of a poverty- and crime-plagued city of 300,000.

But in the past several weeks, in the wake of a tough New York Times profile that suggested his record boasted more razzle-dazzle than substance, he has avoided the spotlight to focus on the prosaic minutiae of city management and assembling his campaign organization. So Monday night’s dinner was a reemergence of sorts.

Afterward—amid a well-heeled crowd that included real estate mogul and Daily News owner Mort Zuckerman, philanthropist Laurie Tisch, and Atlantic Media owner David Bradley—Booker was even more explicit about his Senate aspirations.

He told me he has been interviewing potential campaign managers and other senior staffers in recent days and that he plans to raise $10 million by next January in hopes of discouraging other prospective candidates—such as Rep. Frank Pallone of the Jersey shore district and State Assembly Speaker Sheila Oliver—from opposing him in the Democratic primary.

“My next event is a fundraiser,” Booker confided, noting that even though the hour was late, his night wasn’t over.