Organized, noisy demonstrations are a fixture of election seasons, and they have bedeviled both Mr. Trump and Hillary Clinton throughout the presidential campaign. But the scattered retail rebukes of Mr. Trump are something new: independent acts of protest by everyday consumers who feel that voting against Mr. Trump would not be a sufficient reproach.

They are animated, they said, not just by his inflammatory statements or allegations of predatory behavior toward women — which he has denied — but by the belief that the wealth that powers his candidacy was in many ways amassed on their backs, one best-selling book, dress shirt or hotel stay at a time.

“There’s never been a presidential candidate that’s had a product that I had bought before,” said Nadav Ullman, 26, an entrepreneur who has a standing coffee meeting with his business partner in the food court of Trump Tower in Midtown Manhattan.

Or at least he used to. As Mr. Trump marched toward the Republican nomination, Mr. Ullman was startled by what he saw as Mr. Trump’s strategy of “bigotry and racism.” He moved his weekly meeting outside to a bench in Central Park, grabbing coffee from a Wafels & Dinges vendor on the sidewalk.

“It kind of came down to the idea that going to Trump Tower — in a very small way, no doubt, but in some capacity — would support him,” Mr. Ullman said.