"I guess the difference is that we don't see Canadians coming over in droves and taking our jobs," Towell said.
But Swad is not concerned with knowing which of his customers are American citizens and which are illegal immigrants.
"You know, we're in the restaurant business," he said. "We serve everyone that wants a pizza and has the money to pay for it."
Like so many American success stories, Pizza Patron started simply enough, with one tiny pizza parlor in Dallas. Its original name was Pizza Pizza, just so no one could mistake its one and only product.
When Swad noticed nearly all of his customers were Latino, he changed the name to Pizza Patron, essentially hanging out a "welcome" sign to the Hispanic community.
"Patron means a benevolent leader of the community. The first time I heard that, I thought, man, I like the way that sounds," Swad said.
In a hotly contested business, with competitors on nearly every corner, such Hispanic-friendly touches helped target a rapidly growing market.
Even Wal-Mart accepts pesos at some of its locations near the Mexican border, cell-phone companies such as Movida cater exclusively to Latino customers, and Spanish-language marketing has exploded across American media.
For Pizza Patron, the great pesos controversy has produced some unintended consequences.
E-mail traffic is now running about even between positive and negative messages. Swad, whose own background is Lebanese and Italian, has become something of a hero in the Hispanic community for not backing down to his critics.
"We've had a lot of comments," he said. "People saying, 'You know what? You're not afraid. You didn't back down with all the heat.' So, by not backing down that's a way of sticking up. So we're not gonna sell out our customers."
The campaign appears to be working. The company boasts that business since January has jumped 34 percent over the same period last year, a bump that it attributes in part to the buzz surrounding Pizza for Pesos.
It plans to open many more outlets in the next few years. Pizza Patron is an old-fashioned example of one company finding its niche, capitalizing on opportunity and cashing in.
ABC News' Eric Johnson contributed to this report.