With nearly all precincts reporting, Booker had 55 percent of the vote to Lonegan's 44 percent. The first reaction from the social-media savvy victor came, of course, on Twitter: "Thank you so much, New Jersey, I'm proud to be your Senator-elect."
Booker, who will soon be sworn in as the first black senator from New Jersey, will arrive in Washington from the state's largest city with an unusual political resume.
He was raised in suburban Harington Park as the son of two of the first black IBM executives, graduated from Stanford and law school at Yale with a stint in between as a Rhodes Scholar before moving to one of Newark's toughest neighborhoods with the intent of doing good.
He's been an unconventional politician, a vegetarian with a Twitter following of 1.4 million — or five times the population of the city he governs. With state funding dwindling, he has used private fundraising, including a $100 million pledge from Facebook founder Mark Zuckerberg, to run programs in Newark, a strategy that has brought him both fame and criticism.
Former state Attorney General Jeffrey Chiesa had been appointed by Christie to temporarily replace Lautenberg. The governor scheduled the special election for just 20 days before Christie himself is on the ballot seeking re-election. Democrats said Christie was afraid of appearing on the same ballot as the popular Booker, but courts upheld the election schedule.
Before Lautenberg died, Booker passed up a chance to run against Christie this year, saying he was eyeing Lautenberg's seat in 2014, in part so he could complete a full term as mayor — something he won't do now.
Booker does not expect to be sworn in until close to the end of the month, an aide said, noting the results still need to be certified by the state. Newark's council will be able to appoint an interim mayor when he steps down.
Delli Santi reported from Trenton. Associated Press reporters Geoff Mulvihill in Trenton and Bruce Shipkowski in Bridgewater contributed to this report.