In New York City, Democratic city Public Advocate Bill de Blasio swept to a landslide victory over GOP contender Joe Lhota, former head of the state Metropolitan Transportation Authority.
Detroit businessman Mike Duggan beat Wayne County Sheriff Benny Napoleon to become the Motor City's next mayor.
And in a special congressional election in Alabama, establishment GOP candidate Bradley Byrne successfully fought off Christian conservative Tea Party rival Dean Young to fill the seat vacated by Republican Rep. Jo Bonner, who resigned Aug. 2 to become University of Alabama vice chancellor.
Christie, a straight-shooting 51-year-old who has said he has White House ambitions, trounced Democratic state Sen. Barbara Buono 61 percent to 38 percent in a state President Barack Obama won last year by 17 percentage points.
"I know that if we can do this in Trenton, N.J., then maybe the folks in Washington, D.C., should tune in their TVs right now and see how it's done," Christie told a packed convention hall in Asbury Park.
In Tysons Corner, Va., McAuliffe, 56, a longtime Democratic fundraiser and ally of Bill and Hillary Rodham Clinton, told supporters "What a great night, everybody!" after squeaking past Kenneth Cuccinelli 48 percent to 46 percent to replace Republican Gov. Bob McDonnell.
"I understand emotions are raw -- I get it," McAuliffe said. "I will be governor of all Virginians. I will work with both sides."
His victory marked the first time since 1973 the party that controls the White House won the Virginia governor's race.
De Blasio won in New York City with 74 percent of the vote to Lhota's 24 percent.
It was the most sweeping victory in a New York mayor's race since 1985, when Ed Koch won by 68 points, The New York Times said.
De Blasio, 52, said his overwhelming margin of victory gave him an unmistakable mandate to pursue a liberal agenda.
"My fellow New Yorkers, today, you spoke out loudly and clearly for a new direction for our city," he said at a victory party in the New York borough of Brooklyn.
"Make no mistake: The people of this city have chosen a progressive path, and tonight we set forth on it, together," de Blasio said.
His victory is the first by a Democratic mayoral candidate in New York City since 1989.
In Detroit, Duggan beat Napoleon in the mayor's race, 55 percent to 45 percent.
"Thank you, Detroit. It's been an amazing year," Duggan, 55, told supporters in a hotel ballroom. "We ran a campaign against a very strong opponent."
"I will never forget the way you carried me in the depths of those days when I was thrown off the ballot. And then what looked like an uphill and long-shot struggle as a write-in candidate, and then to victory tonight. No one has had a better campaign organization than the people in this room," he said in remarks quoted by The Detroit News.
Duggan ran a write-in primary campaign and received 46 percent of the vote in an Aug. 6 primary.
Duggan, who will replace Mayor Dave Bing, will have limited powers since the city is run by state-appointed Emergency Manager Kevyn Orr.
The special election to decide the GOP nominee for the vacant House seat left by Rep. Jo Bonner, R-Ala., went to Byrne, a former state senator, who defeated Young, 53 percent to 48 percent.
Byrne, whose brother Dale died of a heart attack Oct. 24, told supporters:"The last few weeks have been difficult for our family."
"The thoughts and prayers and love of so many of you that held us up through my brother's illness and death and funeral and through this election," he said in remarks quoted by the Press-Register of Mobile.
"You couldn't ask for a better group of friends," he said.
Byrne will face Democrat Burton LeFlore in the Dec. 17 general election.