The job will put Christie in charge of helping elect Republicans to governor's offices across the country - giving him a formal national platform and several major political assets as speculation mounts about a potential run for president in 2016.
Christie is expected to travel widely, including planned trips to Pennsylvania, swing states such as Florida and Michigan, and key presidential primary states such as Iowa and New Hampshire. With 36 gubernatorial races in 2014, the visits will allow Christie to use his rising star to boost fellow Republicans, but also to build his national fund-raising network, acquire IOUs, and showcase his tough-talking personality and pragmatic message to voters far from his New Jersey base.
"As head of the RGA, he can do a lot of good for the Republican Party as a whole and, I think, help reestablish us as a party that makes things work again," said Republican consultant Alex Castellanos. "If Chris Christie takes advantage of his post here to help other Republicans, to explain why Republican ideas are working in state after state after state, he'll not only help the party, he'll help himself."
The trips will also test how much of an appetite the rest of the country, and particularly Republican voters, has for Christie's bare-knuckles Jersey style and a record that some conservatives criticize as too moderate.
As governor of a deep-blue state, he has taken some stands - such as accepting a Medicaid expansion tied to President Obama's health law - reviled by the GOP base.
"Is a conservative in New Jersey a conservative in the rest of the country?" Texas Gov. Rick Perry asked this month in an interview with ABC News. Perry, considered a potential Christie rival in 2016, added, "We'll have that discussion at the appropriate time."
Kasich, who called Christie a friend, predicted that voters would be drawn to the New Jerseyan's star power.
"People like him, and he has one other thing going for him - it's called celebrity. In case you hadn't noticed, that's a big darn deal in America today," Kasich said, recalling how Christie campaigned for him in 2010 and threatened to return to Ohio "Jersey style" if voters let him down.
"He will draw crowds," Kasich said, "and he will be effective at raising money, I have no doubt."
Chosen as chairman last year, Christie will replace Louisiana Gov. Bobby Jindal. Christie is reportedly heading to Oklahoma next month to campaign for Gov. Mary Fallin.
Even before Christie formally took over, reporters here were fixated on his national stature, an indication of his rising standing since his reelection this month.
"For 2016, this is just a new platform to articulate his ideas and to show his personality," said Julian Zelizer, a political historian at Princeton University.
But the opportunities come with challenges. For one, as Republican leaders stress that governors are the ones to lead the party to victory, many other state executives are lining up along with Christie to take on that role.
Perry, Jindal, and Kasich are among those considered potential 2016 contenders. Jindal was circumspect when discussing Christie's new role.
"Chris will do a great job," Jindal said. But he sidestepped questions about presidential politics and Christie's future - raised by local and national reporters alike, highlighting Christie's rising status.
"There'll be plenty of time to worry about 2016," Jindal said. "Let's go win 2014, and then let's win the war of ideas before we can win the next election."
Kasich was similarly cautious.
"This is 2013. I don't know what's going to happen tomorrow, let alone what's going to happen in 2016," he said. "Things have a way of twisting and turning, and it's a long way out."
As to how Christie's personality and record will play in the rest of the country, Kasich said, "Chris is a very smart man, and we all evolve in these jobs. We all change."
Christie will have to balance his national role with work at home, where his record will be critical to his political future, Zelizer said.
"He can't remove himself so much during his travels that his standing here in [New Jersey] starts to fall," he said.
Kasich noted, however, that thanks to the media, Christie already seems to have a national stage. After fielding several questions about Christie, Kasich quipped to the assembled reporters, "You all know, you guys can't get enough of him."