Booker will begin his new job with assets few senators enjoy, new or experienced: a national following, a talent for theatrics, and a dynamic cross-cultural appeal that has helped him accumulate 1.4 million Twitter followers.
But after campaigning as a single-handed force for change, Booker is joining an institution where arcane rules and winding processes often chafe ex-mayors and governors who are used to setting the pace - perhaps explaining why only nine of the 100 current senators have been mayors.
Citing Congress' recent conflagration, Gov. Christie said last week, "If I was in the Senate right now, I'd kill myself."
And in 2010, Booker himself said serving in the Senate would mean "discussing rules of procedure until I'm nauseous."
Sen. Dianne Feinstein (D., Calif.), a former mayor, said, "It's very, very different, and it takes a lot of adjustment."
New Jersey Sen. Robert Menendez was the third-ranking Democrat in the House before he joined the Senate, but he recalled old lions such as Sen. Edward M. Kennedy urging him to "take your time, listen a lot, get a lay of the land . . . and evolve over time."
Quiet patience, however, has never been Booker's style.
In August he boasted to NBC News about "finding unique ways for bringing people together and disrupting broken systems, disrupting status quo."
He cited Cruz and fellow freshman Rand Paul (R., Ky.), as well as liberal champion Elizabeth Warren (D., Mass.), as rising senators whose outspoken styles he admired. (Booker has also criticized Cruz's confrontational approach.)
Cruz and Paul are the most prominent examples of a new crop of senators who have defied the old order and used bold stands, dramatic gestures, devoted followings, and social media to promote themselves and their views. Both, like Booker, are seen as harboring national ambitions.
"A senator like Ted Cruz 60 or 70 years ago would have been almost unimaginable," Baker said. "Now you have a much greater diversity of styles."
Booker could be a starry counterweight on the left - and a huge fund-raiser for his party, much as Democrats hope Warren can be.
The upstart methods, though, can have drawbacks. Sen. John McCain (R., Ariz.) famously referred to the Senate's new wave as "wacko birds."
Cruz has inspired conservatives but drawn the wrath of many colleagues, including Republicans, who complain that his tactics have boosted his name but hurt the party.
Lawmakers know who is willing to do the gritty work of legislating and who is mainly concerned with publicity, said Richard Arenberg, who was a Senate aide for 34 years and now teaches at Brown University.
"The coin of the realm in the Senate is still your personal reputation," said Arenberg. "There's only 100 senators, and they all interact with one another, and if you're going to be effective, you're going to have to earn that respect."
Clinton and Sen. Al Franken (D., Minn.) both entered the Senate with star status but were lauded for quietly going to work without coveting fanfare.
Franken, a former Saturday Night Live star, refuses to give interviews to national media. "He was very conscious of that danger of kind of getting the showboat label," Arenberg said.
Booker, on his first day as senator-elect, appeared Thursday on CNN and MSNBC, held a Newark groundbreaking with fellow political celebrity Christie, and did four local television interviews. He spoke to other reporters after the Newark event for four minutes.
As mayor, Booker has cast himself as a man of action. Snow blocking your street? He'll be there with a shovel. Trash not picked up? Text him the location. He might even pull you from a burning building, as he did for one neighbor.
There are no such thrills in "the world's greatest deliberative body," where the emphasis is on deliberative.
Ask Menendez. He has spent years working on immigration reform, saw a deal come apart in 2007, but plugged away until a bill finally cleared the Senate this year. In an interview, he wistfully noted that with the House vote in question, he's still only halfway to success.
Or ask Sen. Pat Toomey (R., Pa.), who reached for the kind of bipartisan deal Booker has lauded: compromising on background checks for gun purchases. Toomey even got a majority, 54 senators, to back him. But because of filibuster threats, he needed 60.
Booker, on MSNBC, said the "fatigue and frustration" with Congress' battles "creates a great climate for change."
But for mayors and other executives used to setting an agenda and quickly following through, the Senate's balky pace can be stifling.
"Being mayor, you keep your own schedule. Here you can't," said Feinstein, a former mayor of San Francisco.
It can take days just to reach a vote, and a single senator can use procedural rules to slow the progress.
"It's not that I decide on a course of action or an idea, and I can just have people execute it for me," said Menendez, a longtime legislator who was also mayor of Union City. "That's the shocker."
Former Sens. Frank R. Lautenberg and Jon S. Corzine both felt constrained after leaving high-powered business jobs for the Senate, Baker said.
Lautenberg adapted and came to love his job as a nuts-and-bolts workhorse. Corzine fled for the governor's mansion before finishing his first term.
Ex-mayors, though, said they also have advantages. After working in cities, they claim a better sense of the ground-level effects of decisions made in the Capitol.
"The real life - not as much ideology," Feinstein said.
Many mayors say their experience handling day-to-day issues gives them a stronger sense of pragmatism, and Booker told MSNBC he would bring a "mayoral attitude" to Washington.
"I know what bipartisanship can do," Booker said after he and Christie broke ground on a new retail, residential, and supermarket project. "It can take a city with a national reputation for crime and corruption and turn it into a national representation of what's possible for cities in America."
In the Senate, lawmakers can also specialize, zooming in on their priorities while colleagues lead on other topics.
"When you're the mayor, everything that happens in your city from garbage to the sewer system to the police department to the budget to snow removal, they're all yours," Menendez said. "In the Senate, he's going to be able to choose the things that he thinks are important to the people of New Jersey and that he's passionate about."