It was just $2,492.63, a pittance, really, alongside million-dollar television buys and direct mail drops.

But with Senator Hillary Rodham Clinton’s bid for the Democratic presidential nomination enduring a rough patch, Peter Semetis, the owner of a deli and catering business in Lower Manhattan, had been following the news and growing increasingly worried that he was not going to be paid for the assorted breakfast trays, coffee, tea and orange juice he had provided the campaign for an event in mid-December.

“I’m afraid of her dropping out of the campaign and me becoming a casualty,” Mr. Semetis said.

So on Thursday, he went to small claims court and filed suit. Mr. Semetis, 53, said he was hardly a political pundit but like others across the country, he had become caught up in the election in the last year and was able to offer some analysis. “There is potential for her to lose Texas,” he said  an assessment not at odds with the polls  “which would pretty much force her to quit.”

Mr. Semetis catered a Clinton event, a rally she did not attend, at the offices of District Council 37, the public employees’ union, on Dec. 15, charging the campaign $2,300, plus $192.63 in tax. Officials promised him that his business, Sale & Pepe Fine Foods, would be paid by check or credit card in a couple of weeks. After a few weeks passed, he started calling to see about the holdup.