Race has been a key theme of the U.S. presidential primaries, with the Democratic vote evenly divided between an African-American man and a white woman. The media is full of complex analysis, but it is a video currently popular on the Web that illustrates some of the grittier aspects of the issue. The video, which first aired on the U.S. channel Showtime, is about a diner called the Weiner Circle. The restaurant, a no-frills burger bar in a prosperous north Chicago area called Lincoln Park, draws customers from the newly gentrified residences nearby: office workers during the lunch hour, students after school, families and singles in the evenings, and a more rowdy crowd once the bars close.

They come for the burgers, hot dogs, fries — cooked fresh, not frozen — and, in the words of Justin DeJong, spokesperson for the Chicagoland Chamber of Commerce, a "unique" experience. Rather than "service with a smile," customers are heckled, insulted and cursed when they order. In turn, they are encouraged to give back as good as they get.

A full list of the daily insults heard would be far too long and not particularly pleasant to read, but the top five words you cannot say on television are everyday parlance. The blasphemy for female dog is popular, as is the four-letter curse word for human waste. "Tip the bucket, you didn't tip sh--," is one way employees make sure they get good tips for putting up with the prolific profanities.

Among the 20-some employees, there are a couple who are Hispanic, but most are African-American, says David Johnston, a server at the restaurant. In contrast, the customers are mainly white. This racial divide becomes more pronounced in the evenings. When people have had a few drinks, they "show their true colours," says Jane, a 30-year-old server who did not want to use her real name. In a city that has a reputation for being hyper-segregated, those true colours can be racist, she adds. "Some customers get into it with us. They think it's a big hangout spot where it's cool to do that."

For example, says Jane, there are people who phone the restaurant to call the serving staff the n-word. "When you answer, they'll say, 'Shut up nigger,' and they will hang up the phone." Others call the staff slaves, or the daughters of slaves, says Roberta "Poochie" Jackson, who cooks and works the cash register at the restaurant. She says she has been called the n-word on a number of occasions, something that is "about as hurtful as it gets." Customers also degrade the staff by calling them monkeys or coons. "We get one or two who say 'Do you have monkeys or coons back there?' That pisses us off."

On occasion, the insults have caused physical fights — Jane once threw pop at a customer who called her the n-word because she was "so mad she wanted to cry." Staff say that when they have complained about the racism, the owners have told them to rise above it. "They [the bosses] tell us to look over ignorant people," Jackson explains.

The owners of the restaurant, Barry Nemerow and Larry Gold, did not respond to Maclean's requests for an interview. However, in the past, Gold has taken credit for transforming what was a run-of-the-mill restaurant into the profane free-for-all tourist destination it is today. The concept has been great for business: according to a recent interview with the owners, profits have about doubled since the abuse began.

The tips are bigger at the Weiner Circle than at other restaurants, says Jane, a mother of two who has worked there the past four years: at night, customers financially reward those who put up with their abuse. "People come from everywhere to come to our restaurant," she says. "Some of them are racist. They come here to get those things off their chests, and there's not really much we can do."