TRENTON -- When Donald Trump makes his first public campaign appearance in New Jersey on Thursday, it won't be one of his typical events.

It's billed as a rally, but unlike the rallies he's held across the country, it isn't free to see the presumptive Republican presidential nominee speak at the Lawrenceville National Guard Armory at 7 p.m.

Instead, tickets are $200, and proceeds go toward helping Gov. Chris Christie, a Trump ally, pay off debt from his own presidential campaign.

"This is really unique in its character," said Brigid Harrison, a political science professor at Montclair State University. "This is akin to Hillary Clinton holding a rally to pay off Bernie Sanders' debt, or to Barack Obama holding a rally to pay off Hillary Clinton's debt in 2008."

Experts say it's not unusual for presidential candidates to host fundraisers or ask donors to help ex-rivals retire campaign debt. Obama did the latter for Clinton in 2008. But it's rare to do so with a rally.

Plus, the price tag runs counter to the populist, "man-of-the people" nature of Trump's campaign, said Matthew Hale, a political science professor at Seton Hall University.

It's like the event "doesn't know what it is," Hale added.

"It's completely bizarre," he said. "But that's what this campaign is all about."

Though Christie ran against Trump for the 2016 Republican nomination, the New Jersey governor has become a surrogate and adviser to the billionaire businessman and former Atlantic City casino mogul since dropping out.

Trump tapped Christie, a longtime friend, to lead his presidential transition team. And there's talk that Christie is in the mix to be the real estate magnate's pick for vice president.

Experts say Thursday's rally -- in which Trump will appear alongside the governor -- could be a favor in exchange for Christie's support.

The governor is still saddled with $250,000 in campaign debt, according to Federal Election Commission reports. And Harrison said Christie "can't move forward politically" without the debt erased.

But, Hale noted, the fact the fundraiser is masquerading as a rally gives the impression that Trump "got scared that perhaps anyone other than Donald might get in the spotlight."

Trump will also appear at a second, private fundraiser Thursday for New Jersey's Republican Party, which still has $525,000 in debt related to legal bills from the George Washington Bridge scandal that engulfed Christie's administration. Tickets for that event: $25,000.

"That debt really puts a stranglehold on the party's ability to field candidates in any successful way," Harrison said. "This is what Trump can do for Christie in the short term."

Neither Trump's campaign nor Christie's office returned messages seeking comment Wednesday.

The appearances come as Trump pivots toward the general election and begins to move away from largely self-funding his campaign.

Trump announced Tuesday night that he is part of a joint effort to raise funds for his own campaign, the Republican National Committee and several state parties, including New Jersey's. The effort is run by Lewis Eisenberg, a veteran New Jersey Republican fundraiser and financier.

Hale said it's possible that with Thursday's events, Trump "is signaling he knows he needs the donor class."

Whether he can win New Jersey in November is another story. Trump is practically guaranteed to win the Republican primary here June 7 -- not only because he is the only GOP contender left, but because a recent Rutgers-Eagleton poll showed more than half of the state's Republican voters support him.

But the poll also showed that in a state where Democratic voters outnumber Republicans nearly 2 to 1, Democratic front-runner Hillary Clinton beats him easily, 50 to 36 percent, in the general election. Democratic challenger Bernie Sanders also beats Trump, 55 to 34 percent.

Another question is how many members of the New Jersey Legislature will line up behind Christie and appear at Thursday with Trump, a candidate who has split GOP politicians across the U.S.

State Assemblyman Michael Patrick Carroll (R-Morris), who supported Ted Cruz for president, said it's a moot point.

"New Jersey is not going to be in play," said Caroll, who noted he won't be at Thursday's events. "Even if all of us advocated for Trump, it's not going to matter."

As for whether tickets are still available to the Lawrenceville rally? Christie adviser Bill Palatucci said he expects it to be sold out "before the doors open."

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.