(CNN) - Republican Chris Christie defeated incumbent Democratic Gov. Jon Corzine Tuesday, giving the GOP a rare Northeast win and a sweep of the night's gubernatorial races.
The former New Jersey attorney general became the first Republican governor of the state since 1997, and the first challenger to defeat an incumbent governor since Christie Todd Whitman defeated Democrat Jim Florio in 1993.
Corzine, who trailed Christie by double digits in several summer surveys, battled his way back to a statistical tie with his GOP challenger for much of the race's final weeks.
Despite Corzine's dismal poll numbers, he came into the race with a solid structural advantage. The former swing state has turned blue in recent years, with a majority-Democratic congressional delegation, two Democratic senators, and a Democratic hold on the governor's mansion for more than a decade.
President Obama, who won the state by a double-digit margin last fall and remains popular in the Garden State, visited several times to campaign on the governor's behalf.
But six in 10 voters in exit polls conducted Tuesday said the president's support for Corzine played no role at all in their decision, with the remainder split almost equally between those who said it made them more likely to back the incumbent, and those who said it made them less likely.
Corzine also was up against history: For two decades, the party in the White House has lost the New Jersey governor's mansion.
As it became clear Christie was going to pull out a win, Republican National Committee Chairman Michael Steele made an unscheduled visit north, after celebrating Bob McDonnell's victory in Virginia's gubernatorial election.
"In a state that overwhelmingly voted in favor of President Obama, this stunning defeat of Corzine sends a clear message to Democrats across the country," said Steele in a statement. "Americans have grown sick and tired of big government and reckless spending, and this vote is a sound rejection of the far-left policies that are hurting our nation."
Corzine managed to win among the one third of voters who cited the economy as their top concern. But he found himself up against the 39 percent who said the most important quality in a candidate was the ability to bring change.
With a tough 2008 election cycle that turned a significant slice of self-identified independents into registered Democrats, and many Republicans into independents, it was clear the independent vote might skew more conservative than in years past.
Still, the fact that Christie won 60 percent of the state's independent voters, according to CNN exit polls, could spell trouble ahead for the White House, especially as Congress begins the critical final debate on the president's health care reform plan.
Corzine fell victim to the same development that hit Democratic nominee Creigh Deeds in Virginia: both men won youth voters, one of the main constituencies that carried President Obama to victory a year ago. There were just a lot fewer of them. Voters aged 18-29 made up just 9 percent of the New Jersey electorate Tuesday, down from 17 percent in 2008.
Democratic National Committee Chairman Tim Kaine downplayed the results in both states, saying it would have been "historic if not unprecedented" for the party to pull out victories in either race.
"In both Virginia and New Jersey we had strong candidates who were running against a significant historical tide and faced uphill battles from the start of this campaign," Kaine said in a statement Tuesday night.
"These races turned on local and state issues and circumstances and on the candidates in each race - and despite what some will certainly claim - the results are not predictive of the future or reflective of the national mood or political environment."
But Republicans insisted the night's results proved the tide had finally turned in their favor.
"While the White House sent their political machine to New Jersey in full force - President Obama and Vice President Biden each campaigning in the state 3 times - even that was not enough to convince voters to ignore the realities of their harmful liberal agenda," said Michael Steele. "I fully expect this trend to continue in the coming months, and President Obama and Democrats should have reason to fear the upcoming elections in 2010."