A rally for Donald Trump in Wildwood, NJ. Kevin Breuninger | CNBC

WILDWOOD, N.J. — On an average day in January, this is a city in hibernation, lying in wait for hotter days to lure throngs of tourists to the neon-lit rows of doo-wop-themed hotels dotting the shoreline. President Donald Trump's campaign rally there Tuesday night, however, brought an unprecedented winter crowd flocking to Wildwood, a 45-mile drive south from Atlantic City — and provided some rare off-season business opportunities for the city. "It's normally dead as dead can be" in January, said Mercedes Delgado, 27, who stood in front of the SeaKist Motel advertising $70 parking spots near the convention center where Trump would speak later that night. Right now? "It's crazy," she said. But even though the event was an economic "shot in the arm" during the sleepy winter, the Trump campaign still needs to pick up the tab, said Wildwood's new Democratic mayor, Pete Byron. "I was told I wasn't going to be invited" the day before the rally, Byron told CNBC in a phone interview. Byron said he was told that "the president was upset that I was looking to be reimbursed for the cost of the event."

A rally for Donald Trump in Wildwood, NJ. Kevin Breuninger | CNBC

That messenger, Byron said, was Rep. Jeff Van Drew, who represents New Jersey's 2nd District, which includes Wildwood. Elected as a moderate Democrat in the 2018 midterms, Van Drew drew national attention — and heaps of praise from Trump — when he voted against the House's articles of impeachment a day before announcing he would switch to the Republican Party. "You have my undying support," Van Drew told Trump in the Oval Office as he made the announcement. Trump, in turn, lauded Van Drew, who stood alongside him at the rally. "What he did was incredible," Trump said, drawing massive applause from the Wildwoods Convention Center. Byron said that Van Drew has been "a personal friend and an ally," adding that the congressman's party affiliation doesn't matter to him. But, the mayor maintained, "I don't think it's fair that the taxpayer should have to support" the considerable costs of a presidential campaign rally. Van Drew's office did not immediately respond to CNBC's request for comment on the mayor's remarks. "This is a promoted rally," he said, not unlike "any other promoted event that goes on in Wildwood." The city had to pay for additional police, firefighters, EMT professionals, public works employees, clean-up crew and other services to accommodate the influx of visitors. Asked if he was going to pursue payment from the Trump campaign, Byron said, "Oh, sure." He expects to get a clearer picture of the event costs in a few weeks, and hopes it can be worked out at the local level "before we have to go any further." The Trump campaign did not immediately respond to CNBC's request for comment.

A rally for Donald Trump in Wildwood, NJ. Kevin Breuninger | CNBC

Reports show the Trump campaign has, at best, a mixed record on paying back the cities that host its rallies. Michigan's Battle Creek Enquirer reported Thursday that Trump reimbursed the Kellogg Arena on costs of about $33,000 associated with a Dec. 18 rally there. But the campaign has reportedly failed to pay back invoices for police and other public safety services in numerous cities, some of which are years old. Unpaid security costs from 10 city governments total more than $840,000, according to a study from the nonprofit Center for Public Integrity published in June. Either way, Byron said that the rally "was a shot in the arm for those businesses" that opened up during one of Wildwood's slowest months of the year. "They say, 'You're a resort, so you must be an affluent community.' We are actually the opposite of that," Byron said. "We don't have very much year-round employment." By Tuesday morning, parking opportunities had become so competitive that Trump fans were ditching their cars more than a mile away from the convention center, which held about 7,500 people. Parking attendants started popping up on Ocean Avenue more than a dozen blocks from the arena itself. Lifelong Wildwood resident Nicholas Ranalli, 30, flagged down cars passing the Water's Edge hotel with a $30 offer: Pay for a parking space and get a cup of coffee free. In an average winter, "there's nobody here," Ranalli said. "Every [traffic] light is blinking ... we usually ride quads around here."

Buttons displayed at a rally for Donald Trump in Wildwood, NJ. Kevin Breuninger | CNBC

One block closer to the rally site, the price per spot shot up to $40 — coffee not included. The roughly 180 spaces available at Aqua Beach Hotel were "almost full" by 2 p.m., said 32-year-old Jonathan Ortiz, an attendant there. On the beachside boardwalk, locals and visitors alike hawked food from stalls and pop-up kitchens, carted folding chairs and hand-warmers around in wagons and, of course, sold all types of Trump-branded merchandise. Some items were familiar — bright red baseball caps and dark-blue T-shirts emblazoned with Trump's campaign slogan, "Make America Great Again," for instance. But some sellers displayed their own merchandise, often recognizable at a distance by a profane or especially pugnacious message. One seller, Erica Van Nostrand, said she had the graphics for her apparel pressed at Seaside Heights, another Jersey vacation spot. Her most popular design: a cartoon-ified Trump urinating on the CNN logo. Michael Foley, 51, traveled from Philadelphia with his daughter to sell a custom-made "Trump car" shirt design. They brought approximately 1,500 shirts to Wildwood, Foley said, and had sold about 600 at $20 apiece with hours to go before the 7 p.m. rally kicked off.

A rally for Donald Trump in Wildwood, NJ. Kevin Breuninger | CNBC