Christie, meanwhile, holds a significant lead in New Jersey's gubernatorial race. A new poll gives him a 20-percentage-point lead over his Democratic opponent, state Sen. Barbara Buono.

Tickets for the fundraiser range from $200 for a reception with the two to $1,000 for a private VIP reception. The invite implores donors to "help send the Jersey conservative to the U.S. Senate."

Lonegan remains the heavy underdog in the race, however, with Newark Mayor Cory Booker (D) leading every poll by double digits. But Christie's help in the race comes despite the fact that the two were old opponents, with Lonegan losing to Christie in the 2009 gubernatorial primary and his aides predicting Christie's loss to then-Gov. Jon Corzine (D).

It will be difficult, however, for Lonegan to make up the ground he needs in time for the Oct. 16 general election in a state as blue as New Jersey.  He's also received help from Sen. Rand PaulRandal (Rand) Howard PaulVaccine 'resisters' are a real problem Democrats fret as longshot candidates pull money, attention Journalist Dave Levinthal discusses 'uptick' in congressional stock trade violations MORE (R-Ky.), a Tea Party darling who visited the state last week to stump with the candidate. Christie was notably absent from the event, citing a prior commitment to his wife.

The two potential presidential hopefuls have sparred over the direction of the GOP, and observers were initially watching to see whether they'd share the same stage, despite their rocky history.

The new Rutgers-Eagleton poll indicates Christie won't be hurt by an affiliation with Lonegan, who is known for bombastic outbursts that can derail his campaign for days.

Christie takes 55 percent to Buono's 35 percent support and leads among independents. He also takes more than a quarter of Democrats and splits the minority vote with Buono, a constituency that typically votes Democratic.

The survey is good news for Christie, who's hoping not only to win in November but to win big enough to make the case during his probable 2016 presidential run that he's the most electable Republican in the primary field. A significant margin in a blue state would boost his argument come November 2014.